When the frontal lobe of the brain developed an estimated 100,000 years ago, it signaled a quantum leap in human adaptation and development. The function of the frontal lobe allows us to grasp the consequences of our actions, to choose between good and bad decisions, to curb unacceptable social responses, and to filter differences and similarities between events and actions.

The frontal lobe is used to retain long-term memories. It enables us to recall events that happened months or decades ago. The frontal lobe is crucial for verbal and math skills. One could call the frontal lobe the CEO of the brain, because that is where the organizing and planning takes place. It’s the part of the brain that allows us to think about our place in the universe. Scientists say that the frontal lobe is what separates man from beast.

It is a different matter when we ask these questions: Where does each individual receive their own intelligence? How much of our intelligence has been shaped by our genetics (nature) and how much by our experiences and the way we were brought up (nurture)?

This nature versus nurture question has been going on since the days of John Locke and René Descartes in the 1600s. Many scientists reach their conclusions by studying identical twins that have been separated at birth. These identical twins had the same genes (nature) but were reared in different families (nurture).

The Minnesota Twin Registry was started in 1983 to catalog and interview all identical and fraternal twins born between 1936 and 1955. Lately, they have added twins born from 1961 to 1964. It is a huge longitudinal study following these twins over many years, using questionnaires to probe their personality, interests, marital status, leadership abilities, finances, and substance abuse, to name a few.

The Twin study has shown that identical twins raised apart show remarkable similarities in lifestyles, interests, attitudes, chosen professions, IQ, and just about every other facet of living. Their conclusion is that genetics accounts for about half of what we are as humans.

The Minnesota Twin Family Study also concludes that environment does make an important contribution to intelligence differences throughout life, and especially in early childhood. Specifically, deprivation in early childhood can stunt the development of intelligence just as it can stunt physical growth.

An IQ test determines a person’s general problem-solving ability and concept comprehension. An IQ test consists of memory recall, spatial, logic, and math abilities. Students in the U.S.  take the SAT or ACT. These tests are not billed as IQ tests but are considered one of the best indicators of success in college. That’s why admissions people look primarily at ACT/SAT scores and class rank in determining who gets into colleges and universities.

            Keep in mind that being “smart” or having a high IQ is just one aspect of a person’s being. An IQ test does not measure creativity, empathy, kindness, or even motivation. Talent cannot be measured accurately by IQ tests, especially in the areas of music, art, dance, writing, social skills, or people skills.