I was inspired by the lecture taught by the WSU Vancouver’s anthropology professor Dr. Hagen. So I decided to post my lecture notes online… This Evolutionary Psychology lecture touched on a subject of parenting, kinship and reciprocal altruism. We’ve talked about mating and parenting, which is similar approach, although with parenting we emphasize tradeoffs. In particular, with parenting we quantified quantity vs. quality. Both investing in offspring. Evolutionary perspective – organism traits are selected to increase reproduction. There are many traits. Another trade off that parents face is (sex bias when it pays in investing in sons and when it is to invest in daughters) which kid to invest in. Why would a mother invest in herself rather than in an offspring – because it is essentially not about the current offspring but the potential of the future offspring. The ability to produce future offspring, or continues successful care.
We looked at the data of infanticide in mothers. Mothers who commit most infanticide are in age less than 20 – these young women commit more infanticides per capita than older women. The interpretation is that they have a longer reproductive lifespan and if it is a bad time for the baby, the easiest thing is to stop that investment, younger mothers are more likely to cut their losses. The 2/3 of infanticide is in South America. What is going on with these mothers – probably resource scarcity – populations without a quality birth control? Similar pattern in a Canadian population, however, much lower rates – infanticide is also more socially unacceptable. So, younger women are more likely to commit infanticide.
Neglect (US data) & abuse by household composition:
Population at large and age of children up to teenagers on x-axis and numbers of victims on y-axis. Infants are more likely to be abused or neglected. They are smaller and are not likely to defend themselves. Once kids become older – the older the kids the more chance to survive. When it comes to the human psychology, not only cumbersome, but the investment in payoff is low. That explains why parents that don’t have enough resources and or have other investments to increase. That is for the population at large. As we move on to the both natural parents, parents who are both biological less likely to neglect or abuse.
Both biological parents are likely to care the most for their offspring. The number increases dramatically by Natural parent + stepparent, natural mother only and finally natural father only. In the single parent cases the lack of investing partner is absent which becomes much more problematic for the parent.
Stepparent is not willing to invest from investment into a stepchild may increase abuse and neglect. Higher rates of abuse than with the single mother, although pretty low, but comparatively higher than other, step parent is not going to invest there is a conflict within the parents over investment in the children – the higher rates of abuse may well reflect that.
Now focusing on stepparents and infanticide – which is in its most extreme form. Turns out that having a step parent is the most highest risk of infanticide in comparison to the two biological parents.
This was the conflicts between parents and offspring, it turns out that conflict between parents and offspring may begin even earlier, in the womb. Maternal-fetal conflict. Baby always going to want to be born, mom is not always have enough resources to invest, nor she may not know who’s kid this is. The genes come from both parents.
Potential conflict here is the father’s genes that come in conflict 50/50. We got a beat dad getting mom pregnant and run off, the chance is mom to raise a kid of a deadbeat – this is called intragenomic conflict. The question is how would that conflict to manifest itself in a womb?
The conflict is nutrients and food between the mom and the baby. If mom has resources she is going to invest into baby, most pregnant women have to eat more often because baby demands it through the umbilical cord, through the placenta. The resource we are talking about the nutrients – sugar in blood. Blood flowing in to the fetus, baby wants more sugar, there is an increased blood flow through the placenta and umbilical cord, the high blood pressure (preeclampsia). Scientifically it has been purposed that this is not a disease rather it is manifestation of the conflict between baby and mom. This baby is a little biochemical factory, baby can pump all kinds of hormones into the system. Baby in a sense can manipulate mom by increasing various hormones in mother’s bloodstream that have the effect inducing high blood pressure in a mom. David Haig has proposed that being a conflict.
Who else needs that sugar – mom does. Another way for the fetus to get more sugar in the blood is to manipulate the concentration of sugar in the blood. Sense the baby wants high sugar, if the baby can prevent mom from sugar is give his/her mom diabetes, which is called Gestational Diabetes. Baby manipulates the mother so the mother has a difficulty digesting sugar.
Two problems of pregnancy – high blood pressure and gestational diabetes – is the manifestation of the conflict between the mother and the fetus. In both cases, it causes the baby to put on extra weight – not too surprising.
When we think of the potential most loving, closest relationship is mother and child – it is hard to imagine that there is a conflict and in some cases extreme conflict such as rejection. When we think of relationships and social relationships in general is a conflict – because we are all competing for the reproductive success. According to this perspective, organisms should have the traits that increase the chance. What about the family members, the people you live with? Mates for yourself, resources for yourself. The other guy is increase in competition with “the other guy.”
Altruism – from the biological perspective – why would anybody help to anybody else… EVER… well anytime you help somebody else you are helping the competitor and not yourself. However, helping behavior DOES occur, when one individual is helping other individual. This was recognized by Darwin, mates are competing for same species. Birds are helping other birds – they are helping species to survive. In 50s and 60s biologist rediscovered that having a species survival does not help self fitness.
What does the altruism mean – there are two parts. Problems with altruism. Providing benefit to another (fitness or reproductive success that is), something that increases the ability to reproduce. And secondly, there is a cost to one’s self – it is a fitness cost – which reduces reproduction.
What do we want to ask ourselves – could altruism ever evolve? If you reduce your fitness how would you evolve this trait of altruism? What would have to happen to that process of altruism possibly evolving? It has to be a some kind of genetic mutation. You got your DNA and the mutation called “altruism” has appeared – a single individual is genetically different, every now and then they would provide benefit to somebody else. This individual goes around and helps others. His fitness is lower, but he may reproduce, some will have one. Others will have more chance to reproduce, therefore, eventually; the mutation is going to disappear. Cannot evolve! Altruism is on a dying streak… But what is the problem???
Things that look like altruism happen all the time, so we are trying to come up with explanations of altruism to explain why is it so common in nature. We have to modify something here. How could the mutation cause the organism to have that mutation? Initially after the mutation has occurred, I recognize if there is an organism with the same altruistic behavior, I would likely to help that mutation to survive. But how do I know that, I cannot “see” genes and if they are altruistic. Chances are they are having to be genetically related, but there is even a simpler explanation. “green beard” altruism theory.
I have a “green beard” has altruistic towards others who have green beards. We recognize that. By providing benefit to them you are increasing the targeted altruism – you are very selective by targeting the “green beard” mutation. Benefit to them has to be greater than a cost to yourself. By benefit we mean reproductively. It only works when you have extra resources that you don’t need. Example – birthday – we bought too much pizza, we are not going to eat that pizza, we could but the benefit is not as much as it would be to the benefit to the other “green beard.” Amazing!!!
I am by far not a psychologist or a scientist, but this stuff fascinates me! What a beautiful and complex evolution of our gene!