The maternal instinct- culture or biology?

Great Debates
1

A simple enough question (ha ha): are women better equipped to care for children (other than the obvious giving birth and nursing aspects) and are children hardwired to depend more on their mothers than fathers or other caregivers?

I once read of a tribe where the gender roles were completely reversed, and the men were expected to take care of the home and children. This seems to imply that much of what we call the “maternal instinct,” is learned rather than instinctive. For example, I know many tricks to caring for children because I’ve heard my older female relatives talking about or emulated my mother, etc. If I was an only child with a small extended family who didn’t see infants and toddlers often, I’d have no clue what to do to them. But since I come from a large, close-knit family where there are lots of babies, I’ve had a lot of practice.

But then I’ve heard of studies where babies responded better to higher-pitched voices, so it seems that maybe they are more receptive to women.

Hmmm.

2

This is NOT directly transferrable to humans, but there does appear to be a bit of instinctive maternal activity among animals.

ANECDOTES ALERT! Our dog had to have surgery that included aboorting her first litter of pups along with spaying. When she came home, she hunted up every stuffed toy in the house, made a “nest,” and placed the toys in it. When our cat had a litter of kittens a few months later, the dog stole one of the kittens and took it to her “nest” where she curled up around it, unharmed.

“Maiden aunt” mice in a cage will babysit newly born pups while the mother is off the nest through the pinky and fuzzy stages of development.

How much of this apparently hormonally driven behavior (dog) or communal pup raising (mice) can be extrapolated onto human behavior I have no idea. There are certainly ample anecdotes of animal (and human) mothers abandoning infants as soon as the birth has occurred.

3

Given how evolution works, it would be highly unlikely for women not to have a maternal instinct. Genetically if not personally, it’s almost always better for a woman to care for her children; not only does she go to more risk and physical effort to produce them, unlike a male she can be sure they are hers. And when something is consistantly true, an instinct tends to evolve to push a species in that direction; I don’t recall the scientific name for the phenomenon. The ( name that starts with B ) effect ? Something like that. And given that humans are a species that tends to produce a few offspring that it invests a great deal of effort on, I’d expect humans to have an extra strong version of it.

On the other hand, such instincts seem to need to be “switched on” in some fashion; if the mother ( or father ) doesn’t bond to the child emotionally, the instinct in question likely won’t kick in. And humans being humans, I would also expect such instincts to be vague; evolved that way because human intelligence can fill in the details ( like language; we appear to have an instinct for the basic structure of language, but the details are learned ).

As for the children, I’d speculate that they’d start out much more instinctively drawn to the mother, if for no other reason than the mother is the one with the milk. Although I recall an interesting study that analyzed baby’s faces and discovered that the people who say things like “he/she has his/her father’s eyes” are quite right; babies resemble the father more than the mother - but not too much. The theory I heard to explain that is that it’s to reassure males that the baby is theirs ( thus the subtle resemblance ), but to also leave some uncertainty just in case the baby actually isn’t his ( which is why the resemblence isn’t too close ).

As the kid gets older, I’d expect his or her instincts to produce more divided loyalties. After all, both mother and father have genes in common with the kid. Also, to keep things complicated, as I understand it it appears that maternal and paternal genes are responsible for building different parts of the brain *, so that would logically produce conflicting instincts due to the different genetic interests involved.

  • As I understand it, while the great majority of genes are inherited from both parents, many are only active depending on the gender of the parent they come from. Thus, for example, a woman born with a single X chromosome will have the edge in social skills etc typically seen in women if she inherits her mothers X chromosome, but will be no better than a male if she gets her father’s X. The genes are there in the secend case, but sealed off; one of the reasons why cloning mammals suddenly became possible was the discover of methods to reactivate those genes, since an embryo with only the genes of one gender active won’t develop properly, such as not forming a placenta ( which the ‘male’ genes are in charge of ).
4

Humans are curious, inventive and adaptive creatures and will try pretty much anything once. However, I would be wary of reading too much into the anecdotal existence of some tribe that inverted the usual gender roles concerning hunting/farming and childcare. To leap from that to assuming that those roles are determined solely by culture would be rather like arguing that, because there was a certain culture that eschewed vaginal sex between men and women and instead favoured anal, the preference for vaginal sex was purely cultural.

If sex roles were assigned purely by choice, it would be reasonable to see a more or less even balance between cultures that assigned them one way and those that assigned them the other. And if there were an advantage to having males be the child-carers and women the labourers, hunters, farmers and warriors, it would be reasonable to expect that to be the prevalent pattern world-wide, instead of a rare and remarkable role-reversal.

5

Hah! Finally got around to finding those cites I mentioned in the other thread.

Here’s an interesting article on the effects of attachment to a parent in general - if you scroll down, more information is provided on how this relates to humans: Addicted to Mother’s Love.

Here is another article that discusses the originating studies of mother-child attachment and subsequent research: Mother-Child Attachment Article. I found this part particularly interesting:

[QUOTE=]
The child’s attachment to the mother appears to begin before birth, when the baby learns about the mother’s voice and odors. Attachment continues afterbirth when the infant learns the mother’s face, and additional qualities of her odors and voice appear to bridge the pre- and postnatal environments.4–7 The maternal odor produces orienting responses and mouthing and soothes a crying infant,6,8 and novel odors quickly acquire at least some of these properties through classical conditioning.9 These odors may have qualities of “safety” or comfort (attenuates crying, orienting) as described in Bowlby’s characterization of attachment. It is quite possible that this neonatal learning about the caregiver is the first postnatal expression of learning within the attachment system and perhaps one of the first ways in which our sense of safety is constructed.

<snip>
However, regardless of the existence of a homologous neural circuitry for attachment, this work suggests that the brain of newborns is uniquely designed to optimize attachment to their caregivers and suggests a new conceptual framework in which to explore human attachments.
[/QUOTE]

According to this and many books about pregnancy, the bond between a mother and a baby begins in utero - the mother’s voice is the most recognizable to the baby, as is her face, smell, etc. I’m sure this would be different if the baby were adopted - eventually, the primary caregiver would be the one with this type of bond.

Also, human babies, as well as other baby mammals, appear to have developed circuitry in the brain that encourages a strong bond between a baby and its primary caregiver.

Supporting Men in the Transition to Fatherhood also includes research that indicates that the brains of men and women and their hormones serve to create a different relationship between a mother and child vs. a father and child (see p. 6):

[QUOTE=]
Although gross differences in the brains of males and females have been recognised for some time, the development of and the integration of neuroendocrine physiology and neuroanatomy suggest that changes in brain architecture under the influences of hormones during the perinatal period can lead to structural differentiation of male and female brain development which in turn can influence paternal behaviours (Durston, 2001; Zeigler, 2000; Fiske, 2004).

Oxytocin, for example, a hormone secreted from the posterior lobe of the pituitary gland, has been identified as necessary for the contraction of the uterine muscles during labour and for effective lactation in female mammals. It has also been implicated in studies of behaviours beyond feeding which maximise the survival of offspring.

<snip>

Since oxytocin activity is implicated in the psychological well-being of mothers, and may be triggered by psychological as well as physical stimuli the investigation of neural pathways may identify physiological contributors to a range of mothering behaviours including the mental and emotional components of mother-infant relationship development (Lippert et al., 2003). For example, preliminary evidence of neurohormonal interactions featuring oxytocin pathways and dopaminergic neurons has been used to offer an explanation of mothers ‘primary maternal preoccupation’ described in the psychiatric literature. (Leckman 2004).
[/QUOTE]

I hope no one got to this before me - it took me half my lunch hour to find publications on the subject that I didn’t have to purchase!