Exploring the role of biological evolution has become increasingly popular in psychology and many related disciplines. It is emerging as a key to understanding cognitive development and has recently been applied to answer why human babies’ brains develop slower than those of most animals. This development period renders them helpless and dependent on others for survival for a longer period of time.
An article published in Scientific American called “The Advantages of Being Helpless” claims that this delay in infants is necessary for facilitating the development of the many “cultural building blocks” (i.e. language) important to dominance over other species.
The article centres on a review of a study featured in the journal Current Directions in Psychological Science, which strongly suggests that helplessness in babies during this period is an adaptive advantage. This period helps them attain complex information processing abilities over other species in the long term. The study shows how the development of the human prefrontal cortex (responsible for decision-making and setting goals) lags significantly behind that of other animals. An example of the lag in cognitive control in children at this stage can be seen in a child’s inability to balance the possibilities of options because they’re unable to direct attention to the task, and will thus always choose the more likely outcome. This lag extends to children’s inability to filter their learning.
The role of biological evolution in psychology was once considered insignificant to the study of the mind. Prominent professors in the Department of Psychology at U of T, however, agree that biological evolution plays an important role. Developmental psychology Professor Emerita, Joan E. Grusec, commented, “the protracted period of dependency is characteristic of humans. [It] means that there is ample time for older members of society to teach complex skills to the younger members. In this sense, humans are different from many other species.”
U of T psychology professor Dan Dolderman says that this period of helplessness could “keep the child in close proximity with parents for a very long time,” and would thereby expose the child to complex processes such as language, socialization, and emotional bonding. This in turn allows the child to build complex abilities characteristic of the prefrontal cortex, such as higher-level cognitive and affective processes.
However, the downfall of the study’s claims that prefrontal cortex development is wired precisely for developing cultural building blocks becomes quite clear when considering the stages necessary for the brain’s evolution. In an interview with The Varsity, professor Jordan B. Peterson, a renowned scholar at U of T, discussed the scope of the study. He proposed that perhaps the greatest disadvantage of this study’s claim may lie in its assumption that the brain evolved precisely for cultural building blocks at the price of an extended period of cognitive immaturity. Adapting cultural building blocks may only be the by-products of a necessary evolutionary adaptation the brain had to make for the greater goal of reducing the possibility of death at birth.
Learning cultural building blocks, such as language, is a goal of development that must occur outside the womb. The delay in cortical maturity is only a consequential factor of the human need to adapt to external constraints such as the high risk that comes along with birth. Many evolutionary changes had to be made to accommodate a decline in infant death. For example, a baby’s brain has adapted to be compressible (in other words, underdeveloped) enough such that it can fit through the mother’s pelvis. This means the baby’s brain cannot be born at a high level of cognitive maturity. The mother’s pelvis in turn has changed to allow the safest possible exit for the baby. These accommodations have reduced the likelihood of either the baby or mother dying at birth.
Other evolutionary adaptations must be taken into consideration when assessing the need for an extended period of cognitive immaturity. According to David Buss, evolutionary psychologist at the University of Texas at Austin, the reason for our prolonged cognitive development is a consequence of the biological need to adapt for sexual selection. The more likely we are to survive, the more likely we are to reproduce.
The extended period of cognitive immaturity can be seen as an adaptive feature for increasing our cognitive power to dominate other species. However, the cause for the extended period undeniably has its roots in a long-standing adaptive chain for pure human survival.
Although there isn’t a conclusive agreement as to why human babies are more helpless than any other species during this stage, the venture into developmental psychology from a biological-evolutionary perspective is far from hopeless.
