The link between intelligence and cooperativeness

In a sample of almost 4,500 men, a positive correlation (.23) was observed between general intelligence and the general factor of personality (GFP). GFP captures one's ability to work well with others. According to the authors, general intelligence evolved to generate more resources while GFP evolved to secure a larger share of group resources.

The positive correlation suggests four types of people, two of which are more common and two of which are less uncommon. The more frequent types are smart-cooperative and dull-uncooperative people. Less common are smart-uncooperative and dull-cooperative folks.   

Rushton's general personality factor: Have you guys been following Rushton's latest work? He's conducted several studies suggesting that there is a general social ability factor, just like there is a general factor for mental ability.

From one of his studies:

The position to be presented here grows directly out of Darwin’s (1871) view that natural selection endowed modern humans with larger brains, increased levels of general and social intelligence, and a more ethical and prosocial personality than ‘‘primeval man and his ape-like progenitors” (p. 159). Darwin wrote of increased levels of human qualities such as ‘‘courage, sympathy, and faithfulness,” and a ‘‘need for approval by others,” with a concomitant decrease in the frequency of ‘‘selfish and contentious people” who ‘‘will not cohere, and without coherence nothing can be effected” (p. 159). Darwin described how moral and inter-personal skills go hand in hand with the greater intelligence modern people possess.

Using structural equation modeling, he shows that personality traits are not orthogonal, and that a general factor can explain more than 50 percent of the variation in the lower-order traits.

To be really reductionist about it, people can be classifed into one of four categories: 1) smart-good; 2) smart-bad; 3) dumb-good; and 4) dumb-bad. And since intelligence and pro-social behavior are positively correlated, as Darwin suggested, there may be more people in categories 1 and 4 than in 2 or 3. This does seem consistent with a rough folk psychology. You could get even more reductionistic and say there are two categories: competent and incompetent, or something like that.

Rushton thinks of the general trait as "social efficiency." Another quote:

In a competitive world, there are always rewards (personal and professional) for more efficient persons—those who are more level-headed, agreeable, friendly, dependable, and open. We close by noting Tolstoy’s (1875/1918) famous opening in Anna Karenina, ‘‘All happy families resemble one another, but each unhappy family is unhappy in its own way.” Perhaps a similar principle applies to individuals: ‘‘All happy [or efficient] people resemble one another; each unhappy [inefficient] person is unhappy [inefficient] in his or her own way.”