While men, unlike women, can continue having children into old age, there could be a price to pay in terms of their child's intelligence.

与女性不同，大龄男性继续生育，所付出的代价是子女的智力。

youdao

The intelligence quotient(IQ ) of each groups dropped step by step with the rise in age, especially for those above 90 years old.

各年龄组智商呈阶梯式降低，90岁以后降低尤其明显。

youdao

One finding of this technique, which is known as genome-wide complex-trait analysis, is that many of the same genetic factors seem to explain why people differ in intelligence in childhood and old age.

WSJ: Intelligence Changes Linked to Genes

Another finding is that people tend to retain a similar "rank order" in intelligence level between childhood and old age.

WSJ: Intelligence Changes Linked to Genes

The new study, published in the journal Nature, offers one of the first estimates of how much genes and the environment contribute to fluctuations in a person's intelligence between adolescence and old age.

WSJ: Intelligence Changes Linked to Genes