It is generally accepted that intelligence is inherited but can also be related to the environment. While studies showed that heredity is an important factor in determining intelligence; it was also suggested that environment is a critical factor in determining the extent of its expression. Studies showed that the grey matter volume is strongly determined by genes, and reflected cognitive performance. It was also suggested that there is a strong genetic influence on IQ, verbal and spatial abilities, So in short our genes determine the quality of our intelligence, our ability to integrate and process information. The level of our intelligence determines how well we cope with changes in our environment. It is believed that race and culture have their share in intelligence as well, but so far there is no confirmed conclusion that intelligence varies from race to race. Environmental factors can play a role as well, but in fact they are capable of slowing down our mental processes more than enhancing it. There is no evidence to indicate that our environment can increase intelligence to a relatively high level. It is also inherently easier to degrade brain tissue than to create more complex brain tissue. Enhancements in brain structure require long periods of evolutionary selection, in addition to the availability of extraneous sources of energy. While brain degradation can happen in a relatively shorter time.