The great-grandmother is learning English with the help of her family when she is at the age of 91. She hopes to use the language at next year’s Olympic Games in Tokyo. Takamizawa was one of the more than 200, 00 people who requested to volunteer for Tokyo’s 2020 Games. English is not required for service, but it is a useful skill for volunteers to have.

But Takamizawa had not been able to learn the language when she was young. Takamizawa said that she was in high school when World War Two started. She said, “In my second year there, English was banned because it was the enemy language.”

Takamizawa said her grandchildren helped persuade her that she was not too old to learn. “When I talked to my grandchildren about my wish, they said, ‘It’s not too late. We will teach you one word a day’ ”. Natsuko is Takamizawa’s granddaughter and main English teacher. Natsuko sends a new English word to her grandmother’s phone every day. They also often work together directly on phrases that Takamizawa will need for the Olympics. “Welcome to Tokyo, this is the Olympic stadium, how can I help you?” Takamizawa answers when asked to say an English phrase she has learned. Natsuko explains that she wanted to give her grandmother something to enjoy. “I can clearly see her English is getting better. It’s my joy now.”

The EF English Proficiency Index is a measure of the level of English spoken in a country. Japan ranks 49th among countries where English is not the first language. This situation is slowly changing as younger generations welcome English. However, Takamizawa believes real change will not happen unless Japanese people become more open to the rest of the world. With around 500 days to go until the games begin, the whole Takamizawa family is ready to welcome the world to Tokyo.

My little grandson Nolan just turned four last week. He loves playing with toy cars. He even sleeps with cars in his hands. So I knew he’d be excited about the car that my husband and I bought him for his birthday.

I talked to Nolan the day I bought his present and told him that Grandmama had something he was really going to like. For the week and a half after that, it was all he could do to wait. He asked if it was big and guessed what it was over and over. And I gave him some strange suggestions. He’d say, “Grandmama, it’s not that!”

The day of his party arrived and as people gathered at Nolan’s house, the pile of presents got bigger and bigger. Nolan came to where I was sitting in the kitchen and said, “Grandmama, did you bring my present?” I told him I did, and we walked into the living room so I could show the wrapped box to him. It was almost as big as he was. A few minutes later, I heard a loud sound and when I looked, he was trying to drag the heavy box into the kitchen. He looked up at me and said, “Can I open it now?” I told him he’d have to wait just a little bit longer until after everyone ate.

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.