Recently there has been much discussion about population decline or even collapse in many developed countries, perhaps even the world. The birth rate of many countries is below replacement rate and has been for a while. The implications of this are described as somewhere between disastrous and beneficial depending on whether the person is looking at it in economic or ecological terms. As always, I like to look at questions in terms of biology, which seems appropriate when asking anything about children. This essay ended up looking at over thirty factors including philosophy, history, morality, education and whatever else I need, but I do have a knack for biology. The main reasons seem to relate to artificial birth control, economics, and concerns about the future. Be aware, I am a fanatic in terms of studying human survival in biological terms, but that can get pretty broad. My conclusions are based on science and reason, but also on evolutionary principles that do not clearly follow those rules. I consider all possibilities even if they are only to increase understanding. This is to consider the reasons for population decline, the implications, and possible solutions. This is all written in the context of ecology, genetics, and survival. I always write in about creating a new ecology that humans survive in long-term to replace the hunter-gatherer ecology we left for the farms and cities of civilization. I look at all of this as being the results of the changes occurring as humans Transition to a New Human Ecology. The first topic to consider is biology. The biggest problem might be that humans do not have very much instinct to have children. Conrad Lorenz explained the relationship between nature and nurture, that is learned behaviors and instinctive behaviors. He described how you have instincts for behaviors, but they mostly just only occur, or are released, when there are environmental triggers or "releases". We do have a great drive for sex and there are old sensory clues as well as cultural clues that can initiate those instinctive behaviors. Sex then naturally leads to pregnancy. That leads to circumstances and hormones that release nurturing behaviors, etc., and eventually adults doing it again, but obviously nature never accounted for birth control technology. We have sex but the outcome is different than it has always been. It does not necessarily result in children, and many are fine with that. Some people do have instincts to have children but again, they are not necessarily strong drives and there may not be much in the way of environmental releases to bring them out. Some women hold a baby and want one. Some women hold a baby and definitely do not want one. Sometimes, men understand just fine, sometimes they just wonder what's going on. Over time, our existing instincts to have children should become more common and stronger as individuals with those instincts are more likely to have children. In ways, this is part of the answer to what might be done about a declining birth rate. If you want your children to have children, give them baby dolls when young. That should initially release instinctive nurturing behaviors. Exposure to and caring for younger siblings or other children would release instincts about children as well. It's All About Choice Now, but then so is the future of humanity. Notice if you take away civilization and its technological capability, you take away that choice. Most of this discussion only applies to a civilization. Without it, the old rules dictated by nature apply, the blunt, red of tooth and claw rules. When survival is a daily affair, survival instincts take over, choices about survival are gone and little of this applies. If we want to be more than animals with all our choices made by nature, then we need to make good choices ourselves. If we do, the potentials will be incredible including achieving most of human aspirations. The responsibilities and challenges of the parents are profound. Raising children is difficult and expensive. A major problem we face now is that market forces do not promote having children, quite possibly the opposite. Employers compete for the time and resources of the parents. Markets tend to be focused on the short term and families are a long-term thing. Children don't have votes and are not notable consumers, so they have little direct political or economic power. Modern forces that promote extreme individualism work against forces that promote children. Kinetic entertainments do the same thing. The Greeks called them "Kinetic Pleasures, distractions and entertainments such as gambling, wine and gossip. Now we have Social Media, Streaming, as well as every alcoholic concoction imaginable and a variety of addictive and non-addictive recreational drugs. Others might call them hobbies or avocations, but those are more likely to lead to self-development. Suffice to say there are an infinite variety of Kinetic Pleasures and distractions available. Realistically though, for maturity people need challenges, adventures, and projects. All of these compete for time in life. Children happen during life and really take time. At a point, one must decide which it will be. Many wait too long to decide, and some pleasures are even unhealthy. At least try to choose distractions that are healthy, productive, or just fun. Where they will lead is unknowable. So, with all those reasons people are not having children, what could change that trend? It is mostly about choices. Children used to mostly not be a choice, but now they are. What are the reasons to choose to have children and families? Social and cultural pressures can promote families, but it is going to have to come down too choice, so while instincts help, people are going to need to have reasons to have children or they will not. Things have changes. The world has changed enormously. The old methods just are not going to work. The easiest target to touch on is the material help of the government, society, and family. Humans are all about learning. They need scholastic, physical, cultural, philosophical, moral, occupational, economic, political, and other forms of education. Everyone should be taught basic home economics, civics and about families. Luckily some of this, such as philosophical and moral education, can come from culture. Some can even come from the Internet. Civilization is based on specialization of occupation and teaching is an old and essential occupation. Much of what else humans need to learn can come from schools and if families or governments want to support children, then they need to support schools. We are lucky to have the incredible educational resources of the Internet, but that does not replace teachers. There are things that parents cannot teach but can come from coaches or perhaps other family members such as aunts and uncles. That has been common in history. It is not always what teachers teach us directly that counts. Often it is what they inform us of or expose us to that we need to learn about ourselves when we are ready. A larger problem might be social and family attitudes. A lot of young parents are on their own when their families could easily be helping them. It's not just that economics have reduced the size of the family. Also, it seems that selfishness has increased. People in general; family, friends, neighbors and society are less likely to be helpful. They are often more busy with other things. Communities are just not there. Everything seems to want our time. That is a social and cultural thing that has gone along with other changes, but again, that is about choices about priorities. About selfishness, that is a general statement and certainly does not apply to everyone. Some families are as helpful as families have ever been, but many are not. I think those families that are family centric more than individually focused are more likely to have children and survive long term. It is always about balance. It has been asked if the traditional multi-generational family is the best form for raising children. Generally, it seems to be... unless the parents are negligent or hostile towards their children. It is assumed at this point, within the bounds of the ecology that I am trying to describe, the family form of "parents" and "children" is the best family form for the wellbeing of the children. It should ensure that the parents are interested, altruistic parties. It is the best place to learn love and it should be the best place to experience love, something of great value to survival. Economics is one of the biggest problems. Raising children in a modern society is very expensive. Healthcare, Housing and Higher education have been called the three H's that are essential to humans. I would include the F's, food and family. The economics of society need to be weighted to help with child raising, certainly until stronger instincts to have children are common, which will be no time soon. A good start is that most industrialized nations have universal healthcare. It is a very good investment in far more than children. Many nations subsidize education, another great investment in citizens and country as part of the national wealth. Housing is currently more of a problem because too often there is a conflict between its value as an investment and a necessity of life. It can have a lot to do with status which is considered further on. A family demands so much of the parents. They should not be punished for it. They deserve an occasional vacation, sometimes with children, sometimes without. The next step in this discussion should probably be about philosophy, to get it out of the way. In terms of children, you would eventually want to examine the existential question of "why". More specifically, why go to all the trouble of having children and raising a family? I generally offer a few answers to that including that it is what you are evolutionarily designed for. Also, it is a drive in human instincts, even if it is not that strong in most people. Children also provide newness, something that is invaluable. Older people have few pleasures but so delight in their grandchildren. Children provide reasons to strive. Children are where we place our hopes and dreams for a life better than our own. Loneliness is perhaps the most common human condition and can be painful. Family is one of the best reliefs to that. A funny thing is that science can help. We all seek security, happiness, connectedness, and fulfillment. Just as philosophy can offer important answers to this problem, so too can science. Science can advise all those things. Science is a powerful tool that can provide information that our thinking abilities can turn into understanding. We can recognize in ourselves what science tells us. Science might not be able to provide happiness, but it can tell much about how to find it. Humans generally do not naturally think that way about our personal lives, but we can use information from science to understand ourselves and the world around us. A primary reason that many people now say is their reason for not having children is because the future does not look like a pleasant place for them. So a vision of a good future could help prevent population decline. I work on that. The overarching story I tell that this essay is part of is how humans can create a fairly stable future ecology that we can survive and develop in long term, based on genetic and strategic adaptation. I think my work gives compelling reasons to think that humans can create a very good world in the future. I see the potential for a pretty wonderful place where we can not only pursue survival, but also development, fulfillment and aspirations. This essay would be about the strategic part of that. Look for "Genetics For A New Human Ecology" at Amazon or an older version on YouTube. You will see I offer one part of a very systematic description of how humans can create a good world that we can survive and develop in long term. The bottom line of that though is about genetics and is that people could be confident that their children would be healthy and better able to adapt to the changing world, another reason to have children. Humanity can achieve the aspirations of our moral instincts and beliefs as well as our aspirations expressed in history and literature. Really though, it comes down to morality. Morality is the outcome of instinctive and learned survival strategies. It is how we decide right and wrong, in terms of survival. Survival requires children, a morality must teach and promote child raising. Instinct is what the genes provide, and genetic husbandry is eventually going to be used to increase that instinct. (Great potential danger lies in that as it naturally leads to overpopulation and demographic warfare, but that is just history. This is perhaps the greatest case where the principle of balance must be respected and embraced, or we could end up with some nasty wars about population.) Population drop off though is so immediate that natural selection is likely to be a dominant factor long before any form of artificial selection becomes a factor. (Besides, trying to husband genes related to morality is a very dicey proposition.) Instincts to have children are not that rare. With that caution, the focus must change to behaviors and beliefs related to having children. That is how to release those instincts. Beliefs and behaviors can not only be learned but since they are elements of morality, they are contagious. Especially when young, humans instinctively look for new moral strategies. If they find something that looks appealing or feels right, it can become part of their moral system. A problem is that morality has changed very like sex. It has become a choice. It used to be based on and enforced by authority and precedence but now with all the changes it will have to be based on understanding or it will not be able to adapt, will not be defendable, and it be not be used. Morality is its own body of knowledge, actually two bodies of knowledge. It is not based on the logic and reason of philosophy or the repeatability of science. It is simply what has worked evolutionarily in terms of instincts and historically in terms of religion. Reason can advise it but does not dictate it. Evolution works by the blunt mechanism of trial and error, but it has had a lot of time to operate. There is a wealth of knowledge and problem solving ability in your moral instincts if you can develop and feel it. Morality "has its own specialized" neural net in your mind, something like a visual cortex is somewhat discrete in the brain. Morality can provide insights that no other mechanism can. Like other things, it takes practice and training to use. That is one of the main functions of religion, developing those instincts. The primary purpose of religion and what gives it its authority, is its husbandry and teaching of morality. Religions only continue to exist if they promote the survival of their followers. Religions retain and teach survival strategies. Some are learned by trial and error, just like evolution - what exists, exists. Some are based on reason or even intuition. Those are the most advanced concepts of morality and the most inspirational. The teaching and fostering of morality, particularly with the intent of releasing moral instincts, is a powerful way to promote families. Survival instincts are similar in ways to moral instincts and also can use learned strategies. It too represents an older part of the brain that is trainable, has its own knowledge and can provide understandings. Moral instincts are how we decide what is right and wrong. Survival instincts are why we decide. There are profound meanings to human survival instincts, but this just does not seem the place for that discussion. If you can figure out the name for human survival instincts though, you can open up a very profound knowledge and understanding. There is the issue of ideal family size. It might seem that two or possibly three children is ideal. Often that will be the case but also there may need to be potential for larger families. That should not be ruled out unless necessary. Human nature is likely to change towards greater instinct to have children, but for a long time, being a choice, many people are going to choose not to have children. Arguably, larger families might also be better environments, if the parents have the energy and resources. At the same time, it seems likely that population growth might eventually become a dominant problem. In some places in the world, it already is the dominant problem. In terms of behaviors, the most obvious thing to look at is cultures that teach and promote child raising. Many sources can contribute to that including parents, the larger family, clans, societies, nations, traditional religions, and spiritual beliefs. The individual's entire society needs to value children. A society that does consider children to be a primary value and activity, is not likely to have a future. This is especially true in terms of predictable natural disasters humanity will face in the future when population numbers suddenly dip. It will happen and we need to have the moral strength to recover as well as that we value human survival. The idea of the importance of human survival as a species is a seed that should be planted long before humanity is threatened and it becomes a necessity. Religions can say that children and even big families are a responsibility, and it is quite practical for increasing the number of followers. Religions with strong beliefs in responsibilities to parents and ancestors can point to child raising as a duty. Those traditional religions have their own problems though and teachings based on religious foundations can lead to problems when those foundations cannot be supported or defended. Understanding and choice are better strategies than obedience in the long run. There are so many beliefs and religions. Those beliefs get called into question. We live in a world dominated by science and in the war between science and religion, science has been mostly winning. One of the last great skirmishes was the Scopes trial. Science does provide great wealth and power, if not necessary as much understanding as philosophy. In any case, science cannot say why to have children. So, if you do not have the authority of religion or science, how can you convince people to have children in such a way that aligns with their instincts? If not religion or science, what could provide that? Yes, philosophy can provide the "why", but that will only be so convincing. I think survival will also depend on an identification with the human species the way individuals have identified with tribes or clans through history. Humans have very strong tribal instincts and that will be important, but it seems that all instincts have a large, learned component. We need to plant a seed, to teach a meme about the value of humanity. This can probably only work in regards to humanity if there is a genetic understanding of our relatedness that feels to our instincts like the relatedness of a tribe. Well, that is something that my book on genetics describes, where cooperation provides a better survival and genetic outcome than competition does. It is not complicated and luckily, we do have instincts for cooperation as well as the more common blind competition more often provided by nature. We must make decisions. With knowledge of the outcomes. I think we will make the "decisions of humans" that lead to win win outcomes rather than the win lose outcomes that out instincts, our "decisions of nature", for blind competition lead to. We have made moral decisions before, when war or greed made the world just too ugly and painful. We have made the moral decisions to create a better world. That is what we need to affirm and then having children will look more attractive. Ultimately though, it will come down to decisions based on moral instincts and understandings. We need to make a world where we have time to slow down and listen to those instincts and understandings. Then, our intuitions may tell us that we are supposed to have families and children. Sex has always been regulated has, primarily to ensure that responsibility is taken for all children. They must be taken care of and raised to maturity such that they can take care of themselves. That will not change. Youth is one of the forms of real wealth and youths must be protected from sexual predators. Related to that is the need to protect the most limited resource, fertile females. That and other things has caused sex to be not just regulated, but frequently considered morally wrong, sometimes just because it brings joy. If you want more children born, even if it is not primarily for reproduction, treat sex as something special, an art to be learned and an activity to be enjoyed that will lead to more families that will be good for raising children. Protect the young because they are the ones that are going to have families. On a more obscure note. One thing that will change relates to status. So much of human behavior revolves around status which is about getting reproductive access to the best genes (getting a superior mate) and to a lesser extent, access to resources for "reproduction". My book, "Genetics For A New Human Ecology", describes why using artificial selection to husband our genes will be absolutely required to replace natural selection that we have removed, calling it human progress. It also describes it as something that we can do ethically and economically. Then better reproductive outcomes will be able to be achieved by artificial selection than could be achieved by competing for superior mates, and at far lower resource requirements. Good genes would be far more common and that should reach that instinct for status. Any change in how status works will be very basic changes to our reproductive habits. It should open up more potentials. Another thing that will change is that generally humans have used a quantity strategy of survival, having as many children as possible and hoping that as many as possible will survive to maturity and then having their own families. As the world has become more complex, we have changed. The time and demands of child raising have increased. We invest far more in each child. We have changed from something of a quality strategy to something of a quality strategy. Husbanding our genetics will mean that we can get the same quality (or better) of genetic outcome raising a few children as from the tradition of raising a large family and knowing natural selection will cull the weaker as it does to animals. Then the idea of having smaller families will feel more natural if we feel that they will have a far better chance of surviving and thriving. Besides, who wants to have their children die because they just were not naturally strong? Humans have strong instincts for both the blind competition of nature and the cooperation we developed as we evolved into humans. We can find both of these in ourselves, our society and our nations. We are developing a new ecology to replace the hunter gatherer ecology we left when we created the farms and cities of civilization. Civilization is our new ecology. It is our life support system and can not only support more people, but also far more human development. It is not an ecology that exists in nature. It must be built and maintained. Our instincts from nature, "red in tooth and claw", can lead to warfare or other destructive competition. The strategies of nature are win-lose. We need to use the instincts for cooperation we developed to survive the last time we made a major change in ecology. We need to use the win-win strategies that are based on our instincts for cooperation that were developed to cope with and escape the horrors of war. We need to explicitly know about both instinctive drives, the blind competition of nature and the cooperation of humans, so that we can choose between them. We are far stronger when we cooperate and work together. In general, teams are far more capable than individuals. Particularly strong individuals need to act as leaders of others. Only then can we create a world where humanity will chose survival instead of being animals. It will work better for everyone and certainly be more pleasant than nature would make it. Just look at how it has been in history. Because of the survival and cost benefit of husbanding our genes, we will take our genetic destiny in hand instead of leaving it to nature. If we do not, we will end up as animals subject to nature. If we take our genetic destiny in hand, hopefully we will take our strategic destiny in hand as well. We can use far more effective and efficient strategies than the blind, uncontrolled competition of nature. We will almost certainly make a choice of what size population can be comfortably sustained by the Earth. That decision involves so many unknowns that I am not likely to make much conjecture about it though between one and two billion people seems a reasonable guess, within a factor of ten. The point of that conjecture is twofold. The first is about the issue of population decline. How many people are needed to support a real human civilization that can support development? Using genetic husbandry, humans should be far more efficient and capable. We are moving towards a reproductive strategy of quality from a quantity strategy. Fewer will be needed to avccomplish as much, but this is another discussion. Let's not talk about overpopulation. That is just an unsustainable horror story. The second point of suggesting that number is that this whole story is about survival. According to the logic of this, there are going to eventually be disasters that wipe out a significant percent of the human population. The decisions will have to be made. Look at it this way. If the Yellowstone caldera erupted, it would kill a huge percent of the people in the northern hemisphere. Their survival would not be dependent solely on luck as is the case with animals. It would be based on decisions they made, moral decisions about survival. Human genetic, social, and cultural development has always proceeded by the coming together of peoples. Nature has always favored hybridization, even though it comes at a cost. Using genetic husbandry, hybridization could be greatly and rapidly increased without the usual evolutionary cost. The genetic wealth of humanity could not only be vastly increased but also dispersed. Different peoples would feel safer and valuable genetic diversity would be preserved. Tribal and racial conflict would have little value. Another problem that needs attention is environmental chemicals that reduce fertility such as phthalates. Already, some nations ban them. They effect males the most, reducing their fertility and reducing their reproductive capacity in a variety of ways. There are other hormone mimicking chemicals used in a variety of products. There is very little systematic examination of industrial chemicals and study is not encouraged by market forces. If you want children though, you need healthy parents, something that is seen more as a profit potential than a necessity for a healthy society and healthy children. Modern, sedentary lifestyles do not help develop good health. This is another reason for governments and society to invest in public facilities that offer opportunities for relationships and families to develop. Physical activities and sports are perhaps one of the best activities that a society can promote for health of parents and families. That is besides their potential for social connections. There are many factors effecting population decline. In ways it is good as the Earth does not have the resources to support the current population. If suddenly though all the food and water needed was available, that would just show other problems like overcrowding and disease. If we want a healthy human population, we need to solve a number of problems. It all comes down to choices. Many factors including instincts need to be understood in order to make good decisions. One thing though, we need to create a good world that we can survive in and that allows us to develop into something good that is in line with our aspirations. We need to create a world where we see a bright future for our children so that we will chose to live. Our moral instincts are too old to use words (though they can understand them) so what they come to us as are intuitions and feelings. It is inconvenient because words are easier to understand, but our instincts can communicate, and we do need to listen to them. When we do we come up with ideas of fairness, kindness, love and even things we would call social justice and peace. We feel the old violent competitive drives from evolution, but humans aspire to those other ways. They are what our instincts tell us are right. We feel that they are right when we work with others. You can really feel it when you work as a team or play with others. Accept it. Choose it. Choose to have a human future. It could be very bright. The reason I describe that though is to reach a description of a feeling that can be expressed as a meme. We know the power of tribalism. It is in our moral instincts, and it is often in our moral systems. The interaction is powerful. The teaching of the meme that "the tribe is of greater importance than the individual" is something naturally that fits into our moral instincts. The value of the tribe to the individual becomes very great and they will do anything for the tribe, even sometimes dying for it. It does not take a lot for a meme to become part of a morality. It is like a seed that takes root and grows if it is nurtured and re-enforced. It will especially grow if it fits into our instincts like tribalism does. If we want humanity to survive, we need a meme that humanity is a tribe and that it must survive. There is currently the difference that we are not as related as single tribes and there are reasons for competition. If though we use genetic husbandry and understand the relatedness of the tribal genes and their mutual value to our survival, our moral instincts will listen. When we must choose whether to survive, our instincts and beliefs will tell us that that is what is right. I have asked people at times what they thought of using artificial selection. Usually, they were not enthused. Then I asked them about it if they knew that they carried a significant genetic weakness. That made them think more. Many do not like the question at all or any possible answer, but one must ask what the place of religion is in survival. Do not even bother to make a typical emotional response. For that matter, forget even using fact and reason. An individual is strong and stronger when inspired. A person is often stronger than that when they are helping others. A person inspired by religion to help others is amazing. The facts are that there is great good and bad to religion, but the only important question is how it relates to survival. In the past, it has been essential to survival, or it would not be so pervasive through history, quite like war. There has always been a conflict between religion and science. About the time of the Scopes trial, science started decisively winning the war. That was obviously good and bad. Science creates great power and wealth. A problem is that science has claimed a monopoly on knowledge and demanded the rejection of most knowledge and wisdom that does not fit in its box. So much has been lost, including philosophy which was the king of knowledge but is widely regarded these days as a dead study. As the limitations of science become more visible, wise people are looking for other knowledge. Science really cannot say why to have children. We need to be open to looking past it. There are many questions it cannot answer, very important questions. Other disciplines are needed to give a broad understanding. The success of a movie or book may very well be dependent on its romantic component. It is often its greatest beauty. It may be the entire plot of the story. Romance is beautiful. Maybe everyone falls in love with the idea of romance. It shows how deeply humans desire loving connections. If we can create a world where human connections and perhaps even romance is possible, it will be a world for families. Humans need and crave connections to others. Stories of romance can powerfully release behaviors that make us strong, inspired and loving. There are different kinds of love. Tomes have been written about them including love that can be quite platonic and eros that can stun the mind. Romance is very popular, but I have trouble defining it in terms of biology and do not have a lot of reason to try. Still, it may be an important component to raising a family. There is another kind of love though that I am sure is. Asked so many times before, what is love? To keep it short I will posit that the most important form of love to a family is a form of friendship. Love is when that friendship grows to something so comfortable, bonding and generous that a family just seems the right thing to do. So if it is children that are desired the question becomes how can friendships be promoted? Looking at modern society it is easy to see that that is missing. Friendships are valued but I think a more clear understanding of their importance are needed. The places and activities of friendships are simply missing. Schools and neighborhoods provided friends but not as much as before. There were places for friends to go to play and grow together. There are far fewer now, replaced by isolation, distraction and money making endeavors. In ways, this may be the biggest cause of childlessness. If there is no public places, there will be few friendships. Sure, couples will still meet, but it is different. They still need the time, skills and habits to become friends. Dance might be one of the best activities to support to lead to healthy families. If you ask a young person in a city what people do for fun and they cannot answer more than "hang out". There is a problem. There must be opportunities for friendships to form and grow. The value of friendship must be understood by the society and individuals. Friendships are not perfect though and an individual must learn how to deal with that to preserve friendships. If we just "swipe left" when someone annoys us, not only is it likely to be a misunderstanding that has caused anger, but it is not going to allow a person to have a sustained friendship. A critical habit an individual needs is to forgive. Children are a bit frivolous and to promote children, some frivolity is needed. It is not a job or wealth that makes people want to have children. It is children that add meaning to life. Public art, music, events, parks, fairs and other frivolous things are what make life worth living. That is where human connections and friendships are made that lead to healthy families. Isn't that what the Ancient Greeks said? Life should be a pursuit of beauty. What could be more beautiful than healthy, happy children? Another problem is that we get older and society gets older. Families are for young people and as people get older, they lose sight of and interest in what younger people feel, want and need. Children need adventure and exploration that older people do not feel the need for and often forget how important it was to them. A society can remind them of that if they know that they should try to remember. There is a great deal that a society and nation can do to promote families. The problems are different and the same in different nations and cultures. Appeals to individuals to have children in terms religion or nationalism will have some success, but not in the long run. What is more important is teaching, from planting little ideas, to explicit teaching, to stimulating instinctive drives. That will effect choices. The truth is that overpopulation has more often been a problem and population decline is currently an issue only because we are in such uncertain and challenging times when there is great change. We do need new strategies. Market forces make child raising extremely expensive at the same time that more resources are required to raise children to maturity. Too often, markets compete with families. The government, society and parents must help make sure it is economically feasible. Places must be provided for relationships and families to grow. Humans need to be nurtured like renewable resources. The seeds must be planted that will grow into family behaviors and release instincts to have families. Children learn by watching and imitate what they see. They need to see families and nurturing. Make sure they know how important they are to you. By adulthood, potential parents must know what their choices are and know the reasons to have children as well as the reasons not to. The moral/philosophical question of why to even have children should be common knowledge. Some will choose not to have children, but many will. It is important that a bright vision of a future can be offered (I work on that). Then comes the big challenge, children. Your responsibility is to raise them to be able to take care of themselves and start their own family. It is hard to say if anyone knows well how to do that. THey have their own instincts and drives for learning and adventure. Luckily, they will help you and they are adaptable, but don't ask too much of them. They will give you a great deal without asking.