The authors formed teams of two, consisting of individuals of different cognitive ability and posed a learning task to them. Not surprisingly, teams with smart individuals learned more than teams with not-so-smart ones. If a team consisted of two smart individuals, then they both learned more than if paired with a not-so-smart individual. When a smart individual was paired with a not-so-smart one, then the not-so-smart individual did not benefit much from the presence of his smart team-mate.
This seems to me to be an extra argument for IQ homogeneity as a creator of wealth. IQ's influence on productivity is not direct but via the medium of learning; that is, high IQ individuals are useful if they acquire some productive skill, e.g., engineering. Ceteris paribus a society with a homogeneous IQ will form groups of similar-IQ individuals more frequently, and this will act as a catalyst, enhancing their mutual acquisition of knowledge. By contrast, in a heterogeneous society with the same average IQ as a homogeneous one, this amplifying effect will not be observed, unless some social mechanisms for cognitive segregation are in place.
Intelligence (In Press)
Ability-based pairing strategies in the team-based training of a complex skill: Does the intelligence of your training partner matter?
Eric Anthony Day et al.
Intelligence researchers traditionally focus their attention on the individual level and overlook the role of intelligence at the interindividual level. This research investigated the interplay of the effects of intelligence at the individual and interindividual levels by manipulating the intelligence-based composition of dyadic training teams. Using a sample of 176 young adult males and a complex computer-based criterion task, homogeneous and heterogeneous dyadic training teams were created based on intelligence scores, and both team and individual performance were assessed throughout 10 h of training. Results indicated a strong additive influence of intelligence on team performance and a slightly positive nonadditive effect in uniformly high (HH)-ability teams. Trainees' individual skill acquisition was strongly correlated with the performance of their teams. However, nonadditive partner effects were observed such that high-ability trainees acquired significantly more skill when paired with high-ability partners instead of low- ability partners, but low-ability trainees benefited very little from being paired with high-ability partners.