Why do some men settle down to form families with the mothers of their children, and others don’t? Biology plays a role. Work published by Lee Gettler of the University of Notre Dame, in Indiana, clarifies how testosterone, the principal male hormone (荷尔蒙), operates.
Previous studies suggest that high levels of testosterone are bad for family life. Fathers with lower testosterone levels provide more child care while high-testosterone males are less likely to stick around. Dr. Gettler has shown something further. This is that a man’s adult testosterone level seems correlated with whether his father was present during his teenage years.
His data come from a survey begun in the Philippines in 1983. This monitored the health and nutrition of 966 men enrolled as babies. It also collected extensive information on whether the fathers of these men were around and providing parental care in the households. It further documented whether participants got married, had children and whether they participated in child care. Crucially, it also measured their testosterone levels at the ages of 21, 26 and 30.
Overall, Dr. Gettler and his colleagues found that on becoming fathers, men had lower testosterone levels if their own fathers had been involved in their care during their teenage years. It has two possible explanations. One is that it is directly genetic (基因的). The other is that teenage experience actually modulates (调节) testosterone levels. This explanation, which Dr. Gettler favors, could lead to high-testosterone men abandoning their sons, who thus become high-testosterone in their turn.
He also found some of those in the survey whose fathers were absent during their adolescence, and who ended up with high levels of the hormone, did become caring fathers. Why this pattern should exist is an unanswered question. But a zoologist looking at these data might take it as an example of developmental plasticity (可塑性), in which the same genes produce different, but appropriate, outcomes in different circumstances.
Dr. Gettler’s discovery throws a useful light on the problem of fatherless families,and how to try to end it.
【小题1】What is Gettler’s study mainly about?| A．Family life. | B．Fathers’ roles. |
| C．Adult testosterone. | D．Child care. |
| A．It was conducted among babies. |
| B．The finding is far from satisfactory. |
| C．The data used were relatively reliable. |
| D．It monitored the nutrition of participants. |
| A．To suggest a follow-up study. |
| B．To contradict Gettler’s ideas. |
| C．To point out the study limitations. |
| D．To give a possible explanation. |
| A．Like Father, Like Son? |
| B．Caring Father, Happy Son? |
| C．Good Father, Good Son |
| D．Love Me, Love My Son |
