We may be slowly losing our intellectual and emotional capabilities due to the lack of evolutionary pressure.

This is according to two articles by Dr. Gerald Crabtree of Stanford University, who reasons that because intelligence was crucial for survival during the early stages of human evolution, there was great selective pressure on genes for intelligence.

But once humans achieved a certain amount of development, the agricultural revolution that led to urbanization, the selective pressures for intelligence weakened, allowing for more mutations on genes associated with intelligence to accumulate.

Dr. Crabtree estimated that all people now carry at least two mutations that could harm intellectual or emotional abilities. In addition, research found that genes involved in brain function are uniquely susceptible to mutations.

The combination of less selective pressure and the large number of easily affected genes could be eroding our intellectual capacities. The good news it that the process is quite slow and we are still smart enough to figure out how to find a solution to the problem, says Dr. Crabtree.

In time we will understand the function of the thousands of genes associated with intelligence and will be able to correct any mutations that may have occurred.