While we are discussing infants, development and nature vs. nurture, it is fitting that Nature just published a new article describing the social evaluation skills of pre-verbal infants (6-10 months old). In a nicely-designed experiment, researchers allowed infants to view a toy as it was made to climb over an obstacle. Near the top, another toy would either help the first toy complete the ascent, or impede its progress by pushing it back. When then allowed to choose one of the second two toys for playtime, the infants overwhelmingly chose the “helpful” toy over the “hurtful” toy. In addition, infants were much more likely to choose “neutral” toys (ones that neither helped nor hindered the first toy’s progress) over hurtful toys and helpful toys over neutral toys. Interestingly, these preference biases evaporated when the eyes (very prominent on the toys) were removed. This suggests that if the babies did not recognize the toys as “individuals”, partiality to helpfulness made little sense, and was thus irrelevant.
These results led the psychologists to conclude that social evaluation skills were inherent to the infants’ repertoire of basic knowledge, something that did not need to be explicitly taught. Obviously this study does not definitively prove that statement, and others have been quick to point out that babies can and do learn a lot through observation between birth and 6 months of age. Therefore, it is still entirely possible that the ability to discriminate between those playmates that will be at worst neutral, and at best helpful, is learned. More work will be required to end this debate, but regardless of the answer, I find this result to be fascinating. Learned or innate, it is cool that infants can process this information and seemingly act in a manner to engage in or avoid relationships that could potentially be beneficial or damaging, respectively, to them in the future. I mean, who wants to play with a bully?
As a social creature, humans need to be constantly evaluating social cues to provide for a successful navigation through our intricate little world while minimizing conflict. This skill has existed for thousands of years, with individuals persistently assessing potential threats and possible alliances in order to increase the odds of survival. We even learn to avoid dangerous encounters with other creatures based on particular cues and circumstantial evidence (anyone who has ever hiked in Glacier National Park can tell you exactly how NOT to run into a bear). It is therefore no surprise that other animals do this routinely as well. This is done not just to identify conspecifics who may hurt or harm them, but also with regards to other species. Several different animals have distinct alarm calls depending on exactly which predator is near, since escaping predation is not a one-strategy-fits-all venture. I’m telling you all of this because I also wanted to mention another study I recently read about that probably doesn’t deserve its own entry, but is still interesting. It involves behavior pattern selection, so I think it kind of fits.
Researchers from the UK and Nairobi determined that elephants could distinguish between at least two different Kenyan ethnic groups and identify them by olfactory and color cues independently. The young men from one herding tribe spear elephants as a demonstration of strength and virility, while a second group of farmers pose little to no threat. Elephants reacted aggressively and exhibited more fear when detecting the odor from garments worn by the spearing tribe, or encountering the distinct colors typically worn by these tribesmen. Little response was elicited from either the odor of the farmers’ garments or the color of their clothing. Interestingly, prior experience of the pachyderm family to spearing had no effect on the extent or nature of the reaction by the group as a whole, but individual experience (actually having been speared in the past) did elicit stronger reactions by those wounded elephants to the herding people. Therefore, elephants demonstrated an ability to categorize humans into subgroups and react appropriately, depending on the threat level being faced.
Given the advantage that this type of processing could confer, the researchers predict that this discriminatory ability will prove to be widespread among animals with appropriate perceptual and cognitive capacities. So perhaps it would not be surprising at all if human infants do have some innate ability to discriminate and process cues in order to determine their best course of action. But certainly, that skill will be modified by experience.
Hamlin, J., Wynn, K., & Bloom, P. (2007). Social evaluation by preverbal infants Nature, 450 (7169), 557-559 DOI: 10.1038/nature06288