Intelligence Manifest
How do we acquire impressive IQ scores, and why does it matter for our survival?
Innumerable social relations held an imperative role in our ancestors survival; ensuring they weren’t tricked, could maintain friendships, and deal with rivalry helped secure their place in the tribe. Without this social standing, our forefathers would have been left to guard themselves alone against the malevolent forces of the wilderness. This is evidenced by Kross, Berman, Mischel, Smith and Wager (“Social rejection shares somatosensory representations with physical pain,” 2011), who found that “when rejection is powerfully elicited,” it evokes activity in “areas that support the sensory components of physical pain (secondary somatosensory cortex; dorsal posterior insula).”
However, in a contemporary setting, where written language and logic reign supreme, these may prove to be useless. Although many systems (such as education, health care, benefits etc.) are set in place by the government to ensure you don’t waste away, Batty (“Premorbid [early life] IQ and Later Mortality Risk: Systematic Review,” 2006) found from a compilation of adult based studies that “those with higher scores on tests of mental ability had lower rates of later all-cause mortality.” So, it seems, with a higher IQ, you have a longer life span.
But where does intelligence come from? First consider assortative mating, a pattern in which people with similar phenotypes are more likely to mate than in a random pattern. Of course, this may match myriad other factors, such as weight, height, or other clearly visible characteristics rather than just intelligence.
It’s no secret that brain structure can affect behaviour, and that brain dysfunction may be due to genetic inheritance. Three dimensional maps of brains have frequently been used to illustrate how similarity of brain structure increases with increasing genetic affinity.
In an international collaborative study, Zhang, Cheng et al.,(“Neural, electrophysiological and anatomical basis of brain-network variability and its characteristic changes in mental disorders,” 2016) measured blood flow change in an attempt to monitor interactions. This was done in order to establish frequently changing neural connections. It seems that variety really is the spice of life, as those with a higher variability also had a higher IQ. Furthermore, areas of the brain associated with functions such as vision and hearing showed lower variability than those associated with development and learning.
Despite all this, it is inarguable that environment also has a massive impact on intelligence, which Vygotsky’s proposal of the zone of proximal development and extreme abuse cases all show. Take, for example, Genie, a child who had been tied to a potty chair and isolated in a single room for 13 years of her life, subsequently not developing verbal skills and being unable to retain future lessons from therapy. Although cases like Genie’s are incredibly (and thankfully) rare, these illustrate the importance social influence also has over cognitive development.
