There are some theories that human collective intelligence is rising with each generation.
Researchers from the University of Aberdeen and Scottish health board,
found a spread of 3.7-IQ in two groups born in 1921 and in 1936.
Study says, that this may be because each generation seems to have a higher
standard of living than the previous one (considering medical care, education
and job opportunities), leading to higher performance.
This has been called the Flynn Effect – which also theorizes that improvements
in nutrition, health and other factors lead to higher cognitive functioning.