have noted a positive relationship. A 2016 Pew Center global study on religion and education around the world ranked Jews as the most educated (13.4 years of schooling) followed by Christians (9.3 years of schooling). The religiously unaffiliated—a category which includes atheists, agnostics and those who describe their religion as “nothing in particular”—ranked overall as the third most educated religious group (8.8 years of schooling) followed by Buddhists (7.9 years of schooling), Muslims (5.6 years of schooling), and Hindus (5.6 years of schooling). In the youngest age (25-34) group surveyed, Jews averaged 13.8 years of schooling, the unaffiliated group averaged 10.3 years of schooling, Christians averaged 9.9 years of schooling, Buddhists averaged 9.7 years of schooling, Hindus averaged 7.1 years of schooling, and Muslims averaged 6.7 years of schooling. 61% of Jews, 20% of Christians, 16% of the unaffiliated, 12% of Buddhists, 10% of Hindus, and 8% of Muslims have graduate and post-graduate degrees. The study observed that the probability of having a college degree in the U.S. is higher for all religious minorities surveyed (perhaps partly due to selective immigration policies that favor highly skilled applicants), including the unaffiliated group which ranks in the fifth place, being higher than the national average of 39%. Factors that influence IQ Environmental and genetic factors play a role in determining IQ. Their relative importance has been the subject of much research and debate. Micronutrients and vitamin deficiencies Micronutrient deficiencies (e.g. in iodine and iron) influence the development of intelligence and remain a problem in the developing world. For example, iodine deficiency causes a fall, on average, of 12 IQ points. Heritability Heritability is defined as the proportion of variance in a trait which is attributable to genotype within a defined population in a specific environment. A number of points must be considered when interpreting heritability. The general figure for the heritability of IQ, according to an authoritative American Psychological Association report, is 0.45 for children, and rises to around 0.75 for late adolescents and adults. It may seem reasonable to expect genetic influences on traits like IQ to become less important as one gains experiences with age. However, the opposite also could occur. Heritability measures in infancy are as low as 0.2, around 0.4 in middle childhood, and as high as 0.8 in adulthood. One proposed explanation is that people with different alleles tend to reinforce the effects of a particular gene,