Dadly adaptations

In some species, males help take care of their offspring.  This is common in birds (~80%); uncommon in mammals (~6%), but it does occur – in wolves, for example.

In particular, humans exhibit paternal care, although the extent varies.

There are indications that this behavior is  not purely cultural, not just learned, but has a biological substrate.  Married men, and especially men with children,  have lower testosterone levels, and it seems that this is causal: marriage possibly, and children probably, drive the reduction.  At this point we don’t know the exact triggers, or the biochemical mechanism. This pattern of testosterone reduction associating with paternal care is seen in many other species, and it might be that studying some of those other species would help us figure this out.  However, since gorillas don’t show much paternal care, while chimpanzees show none at all, it seems likely that paternal care arose independently in humans. There’s no guarantee that our mechanism is the same as that in wolves.

If we understood how this works, we might find that individuals and populations vary in  their propensity to show paternal care ( for genetic reasons). I would guess that paternal care was ancestral in modern humans, but it’s easy enough to lose something like this when selective pressures no longer favor it.  Wolves have paternal care, but dogs have lost it.

This could have something to do with better health in married men. High testosterone levels aren’t cost-free.

It’s possible that various modern environmental factors interfere with the triggers for dadliness. That would hardly be surprising, since we don’t really know how they work.

All this has a number of interesting social implications.  Let’s see how many of them you guys can spot.

 

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38 Responses to Dadly adaptations

  1. Racial differences in paternal involvement; higher levels of aggression in the unmarried or frequently married (the higher levels being achieved between marriages); higher levels of violence against spouses in briefer relationships; more children sired by the least parental men (because the costs are very much lower) and, in such men, a great sentimental fondness for dogs.
    If I had already had my morning coffee, the list would be longer.

    • Jack says:

      >There are indications that this behavior is not purely cultural, not just learned, but has a biological substrate.

      I’m interested in how a long held cultural norm encouraging paternal care might interact with selection on the genetic predisposition. The cultural norm might be largely epiphenomenal to the genes. But in addition to cultural variation *due* to genetic variation it is also possible to see variation in the ratio of culture to genes that provides for paternal care, right?

      So undermining or dismantling cultural norms of paternal care could have a different effects on different populations.

      In general, I don’t have a good sense of how I should expect the cultural norm and the genetic predisposition to interact. Do they compliment each other or undermine each other? On the one hand they should reinforce each other: people are more likely to boost norms that they are adapted to and that improve the status of their behavior. And social and criminal punishments for violating norms often have a fertility penalty.

      But at the same time the norm reduces variation in the behavioral impact of genes which reduces selection (cads are forced to act like dads). Conversely, we see genetic dispositions that are so strong that they can do the job without any kind of cultural institution.

      Is there a general answer to this question? Data? Or do we always have to evaluate the relationship on a case by case basis?

    • Jack says:

      Sorry, my comment wasn’t meant as a reply to you.

    • melykin says:

      You are saying high levels of aggression, violence against spouses, brief relationships, and more children sired, are associated with a great sentimental fondness for dogs?

      This sounds crazy to me. Unless you consider people such as Michael Vick has a sentimental fondness for dogs (which of course is absurd).

  2. ziel says:

    We might find that immigrants from more traditional societies lose some of those strong family values after a generation or two in the modern American economy.

  3. JayMan says:

    One obvious difference between dads and cads: the vasopressin receptor gene: AVPR1a

  4. dave chamberlin says:

    Different feedback payoffs for different types of human societies. Hunter gatherer groups where mom gathers most of the calories and dad jaunts back in now and then with a carcass evolve a less caring dad and looser rules on monogamy than a pops who is generally a stones throw away tending the crops. Clamp down the Malthusian trap on an agricultural society long enough and hard enough and Bantu dads (farming is womans work) are going to be weeded out.

    • Paul says:

      Isn’t there more pressure towards monogamy or perhaps lower levels of polygamy in that hunter-gatherer scenario? I don’t believe moms would be able to obtain enough calories by gathering nuts and berries. They would have to depend on the dads and their hunts for sufficient calories.

      Agriculture increases the amount of available calories and may increase the potential for polygamy. The strict morals and religious rules that instituted monogamy or limited polygamy in many agricultural societies may have been a counter-balancing adaptation for formerly hunter-gatherer populations that were inclined towards lower levels of polygamy than made possible by agriculture.

      I’m not sure it’s clear that the Malthusian trap is ultimately effective in weeding polygamous types from agricultural societies, if we define “polygamous types” as those effective at obtaining elite positions of high social/sexual status which can be and are used for polygamous relations. The elites in civilization don’t tend to be the best farmers. It’s not clear that the traits that makes one a good farmer are the same or overlap enough with the traits that make one adept at obtaining elite status in civilization.

    • teageegeepea says:

      I would have thought that Malthusian equilibrium tends to be reached in a pretty short span of time, short enough that the Bantu would have hit it soon after their expansion (which Razib recently dated to about 1000 BC).

    • John says:

      Isn’t there more pressure towards monogamy or perhaps lower levels of polygamy in that hunter-gatherer scenario? I don’t believe moms would be able to obtain enough calories by gathering nuts and berries. They would have to depend on the dads and their hunts for sufficient calories.

      Agriculture increases the amount of available calories and may increase the potential for polygamy. The strict morals and religious rules that instituted monogamy or limited polygamy in many agricultural societies may have been a counter-balancing adaptation for formerly hunter-gatherer populations that were inclined towards lower levels of polygamy than made possible by agriculture.

      I’m not sure it’s clear that the Malthusian trap is ultimately effective in weeding polygamous types from agricultural societies, if we define “polygamous types” as those effective at obtaining elite positions of high social/sexual status which can be and are used for polygamous relations. The elites in civilization don’t tend to be the best farmers. It’s not clear that the traits that makes one a good farmer are the same or overlap enough with the traits that make one adept at obtaining elite status in civilization.

      • Greying Wanderer says:

        “Isn’t there more pressure towards monogamy or perhaps lower levels of polygamy in that hunter-gatherer scenario? I don’t believe moms would be able to obtain enough calories by gathering nuts and berries. They would have to depend on the dads and their hunts for sufficient calories.”

        The ability of females to gather enough calories for their offspring on their own would be the critical factor imo but female apes do and assuming humans started off that way then i think it’s reasonable to assume that was the default state – an environment where females could gather enough calories to feed their offspring on their own.

        I’d suggest moving* into environments where that wasn’t the case would be the driving force for a lot of adaptations.

        (* alternatively climate change expanding the default environment and then changing back leaving unadapted populations stranded and needing to adapt in a hurry.)

      • John says:

        True, but female apes live in jungles and forests with lush, edible vegetation. I think humans developed after apes left these kinds of environments for the savannas. They became hunter-gatherers in environments without lush vegetation and fruit everywhere.

      • dave chamberlin says:

        People are right to question my earlier statement regarding hunter gatherer groups tending towards polygamy because the ones we know of don’t. The hunter gatherer groups we know of existed to near present times by living in fringe environments, deserts, arctic regions, or rainforests. But these hunter gatherers are barely getting by and such a luxury as extra wives isn’t in the cards. But in most of human history hunter gatherer groups were not overwhelmed into unwanted corners. We had a brief glimpse of what life would be like for agriculturists/hunter gatherers in prime food collection locations in North America for a very short time before diseases spread and obliterated their way of life. The Amerinds of the east coast of what is now the United States were far larger than the Europeans at first contact because they kept the surrounding countryside at one third holding capacity through constant war with their neighbors. That means a lot of men killing men and a lot of women left over for polygamy. So I don’t trust what we theorize regarding hunter gatherer groups from those sad scraps of humanity we now call the last hunter gatherers because they are atypical. But nothing can be stated for certain because so little is known about human pre history.

        But polygamy or monogamy isn’t the point. Lazy men who do little to raise their kids are going to get weeded out given enough tough times and competition from dads who do. Question. I would expect herbivores to by and large comprise the 94% of mammals where fathers don’t raise their young and carnivores to make up the remaining 6%, but I don’t know.

      • John says:

        Well if you want to look at warmer climates, I believe the hunter-gatherers in Africa like the Bushmen were/are less polygamous than the Bantu agriculturalists.

      • teageegeepea says:

        It was also my understanding that hunter-gatherers are more monagamous than their agriculturalist neighbors.

    • The fourth horseman of the apocalypse says:

      Until the development of the steam engine and the internal combustion engine, weren’t we all under Malthusian conditions?

  5. Abelard Lindsey says:

    This could have something to do with better health in married men. High testosterone levels aren’t cost-free.

    On the other hand. low testosterone levels are associated with increased risk of cardiovascular disease, increased visceral fat, muscle and bone loss (sarcopenia and osteoporosis). Of course all of these are anathema to good health.

  6. Fourth doorman of the apocalypse says:

    Those men whose T levels reduce after successfully finding a mate will spend less time finding additional matting opportunities and more time investing in their future offspring.

    This will allow them to accumulate wealth, which others with higher levels of testosterone will want to steal. Of course, each side will rationalize its behavior.

    After a while, certain groupings will arise and lead to civilization.

  7. Wolves routinely live in packs, dogs not so much. Most cat species don’t exhibit paternal care, but lions and feral house cat colonies do, at least to some extent. Humans in civilizations do (at least the ones who created the civilization, not so much hangers-on), not so much hunter gatherers. So, is it related to living in close proximity to the offspring, and is there some identifiable hormonal component?

    • Fourth doorman of the apocalypse says:

      Cooperation by more distantly related males seems to be an important aspect of civilization.

      • IC says:

        Cooperation is sign of tribal society
        Obedience to hiearchy or lords or law is sign of civilization. In civilized society, rules or order overide any kinship.

  8. melendwyr says:

    Well, the implications for novelty-seeking and risk-taking are obvious – more curious are the possible consequences involving social dominance. If I recall correctly, dominating a social interaction raises testosterone, and being dominated lowers it, which suggests that low-ranking members of the social hierarchy would be better fathers.

    I wonder if that would be an intended consequence of certain patriarchial religions, in addition to the obvious organizational benefits – making men take better care of their children by manipulating their feelings of dominance.

  9. Greying Wanderer says:

    1. Women’s tears reduce testosterone (or so i read on the interwebz)
    2. Men with young children have reduced testosterone (or so i read on the interwebz)

    This makes me wonder if children’s tears also reduce testosterone?

    (Or in fact if all tears reduce testosterone hence the taboo against men crying. That should be easy to test with a T test-kit and some onions?)

    Men with a violent streak and children who won’t stop crying are a dangerous combination so i think if tears do reduce testosterone that may be why i.e. an adaptation from the time when men first started hanging around after the birth of their kid (or after pregnancy even).

    If so men from populations who hadn’t gone through that process wouldn’t have that fail-safe built in.

    • melendwyr says:

      I don’t think crying and watering eyes are equivalent, hormone-wise.

    • Greying Wanderer says:

      Further thought.

      A lot of violence towards babies and very young children happens when they won’t stop crying – hence the thought that children’s tears might reduce testosterone in the same way that women’s tears apparently do – and thinking on it further that kind of violence is more prevalent with step-fathers which makes me wonder if, *if* children’s tears do have that effect, does it have less of an effect on non-kin?

  10. Rudolf Winestock says:

    “It’s possible that various modern environmental factors interfere with the triggers for dadliness. That would hardly be surprising, since we don’t really know how they work.”

    So environments that interfere with dadliness will exhibit lower paternal investment. It would seem that people from such environments will be out-competed by those whose environment does not have such interfering triggers. Here’s an interesting wrinkle: It looks like the present high-prestige culture has many triggers that interfere with dadliness (e.g., the sexual revolution, easy divorce, et cetera). So current attitudes are self-limiting in the long run.

    That’s the easy, obvious answer for your request for implications.

    Humans, of course, aren’t automatons; we can see the implications of current attitudes. People were decrying the “race suicide” aspect of birth control back when Margaret Sanger was still pretty. So a secondary consequence of this is that people see the implications of an environment that interferes with dadliness and try to do something about it.

    Assuming that there were no opposition from the chuckleheads (call me a dreamer), how would they do it? Passing laws wouldn’t be enough. Civil authority is a blunt instrument; too many people would find loopholes or bribe law enforcement. One would have to rethink social relations in such a way that dads would have an obvious and impossbile-to-emulate advantage that could not be negated even in the short term. And this would have to obtain even in a high-tech environment.

    Hmm. This calls for some more thought.

  11. j3morecharacters says:

    The social implication of modern environmental factors that interfere with the triggers for dadliness is the dissolution of the family. When men lose the urge to care for their children, the society will step in and try to force them to pay alimony and play dad. In fact, the State will create indoctrination courses to teach dadliness to unwilling males. Modern society has already developed a judicial/bureaucratic/penal “apparat” that ensures that fathers will not be able to abandon their children. As dadliness declines, this mechanism becomes more tyrannical. Spontaneous traditional family structure will be (or already is?) gone.

  12. j3morecharacters says:

    Dadliness or paternal care may have been enforced in the past by females by controlling sexual access. The environmental change killing dadliness is no other than the general sexual freedom that has deprived women of this trigger, Of course this is half baked speculation. It could also be a parasite.

  13. Greying Wanderer says:

    @John
    “True, but female apes live in jungles and forests with lush, edible vegetation. I think humans developed after apes left these kinds of environments for the savannas. They became hunter-gatherers in environments without lush vegetation and fruit everywhere.”

    Could be but i don’t think it changes the point. If it didn’t all happen overnight there had to be a sequence and assuming we started at apes that sequence started with environments where females could gather enough calories to feed their offspring themselves.

    At some point like you say early humans got into environments where that wasn’t true and had to adapt but at that point they’d still be in the default state. Adapting to that environment could have involved pair-bonding and males starting to help for that reason but could also have been simply polygynous sex for food or later weaning or female sibling cooperation or grandmothers). I don’t think pair-bonding is the path of least resistance option except in environments where a male provider was the only option.

  14. Matt says:

    Testosterone declines as a function of age, so if successful paternal investment is partly a function aided by lower testosterone, then a population which moves to a high paternal investment norm and does not have a mechanism to lower t upon pair bonding may find that older fathers are relatively more successful.

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  16. j3morecharacters says:

    Another social outcome will be that many, most of all children will grow up without in-home fathers. Psychologists say that fathers are necesary to develope a healthy personality. Probably true.

    • misdreavus says:

      Psychologists say that fathers are necesary to develope a healthy personality. Probably true.

      Probably not. Says nearly every longitudinal adoption study.

      • The fourth doorman of the apocalypse says:

        This is curious. I was not aware that there were many adoptions by single women. Perhaps there is, however, perhaps your point is that the studies demonstrate that bio fathers (and perhaps even bio mothers) are not necessary.

        I would not expect bio parents to be absolutely necessary because I doubt there has been any selection for infants to refuse the input of anyone but their bio parents. Surely, having adoptive parents is considerably better than having no parents (because you would likely end up dead if you have no parents.)

        However, bio parents might be marginally better than adoptive parents.

  17. j3morecharacters says:

    As it is now, adoptive parents tend to be more educated, more adult and stable than biological parents. Today, adoptive parents are selected among many candidates. Of course, if child abandonment is the rule, then there will be more adoptable babies than families wishing to adopt.

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