In the past, many people believed that infants developed attachments or bonds with only those who took care of the infant’s physical needs, for example, the need to be fed.  This led to a number of debates such as whether mothers should go out to work.  As a result of these debates, psychologists began to study the development of the relationship in great detail, and found that things weren’t nearly so simple.  For one thing, many babies develop special attachments to more than one person, and sometimes they will develop a special relationship with someone that they see only for a relatively short period each day.  A pioneering study by Shaffer and Emerson, conducted in 1964, found that many of the infants they were studying had special attachments with their fathers who were out at work all day, as well as with their mothers who were at home.  Some other babies, however, didn’t form attachments with their fathers.  Furthermore, some formed attachments with the fathers, but not with their mothers, even though it was the mother who was with them most of the time.

What made the difference?  The above study found that it was the quality of social interaction between parent and child which affected the infant’s response.  Babies become especially fond of parents (and others) who are sensitive to the signals they are giving out smiling and other facial expressions, movements and so on and who are prepared to interact with them in their playing.  They don’t develop attachments to people who care for them physically unless they also talk and play with them.

Even though parents become attached to their infants very quickly, it takes longer for the infant to develop its own attachment.  Although infants often prefer to be with one person, in the first few months they are rarely upset if that special person is not present.  Psychologists found that the full attachment would appear at about seven months.

This attachment forms the basis of the loving relationship between parent and child, which persists throughout life (if it is not purposefully damaged).  And that attachment, in its turn, has been based on the quality of the interactions between the parent and the baby.  A natural ability to interact with people and to form relationships with the people who respond to you sensitively is common among human infants all over the world.  It is, quite literally, part of our heritage as human beings.〔熊本大・407語〕



1 過去には多くの人が,乳児は自分たちの身体的な要求,たとえば,食べ物を与えてもらうといった要求のめんどうを見てくれる人々にだけ愛着[愛情]やきずなをもつようになると信じていた.このことにより,母親は外に出て働くべきかどうかというたぐいの議論が多く起こった.このような議論の結果,心理学者はきわめて詳細に(人間)関係の発達の研究を始め,物事[事態]は決してそんなに単純ではないことがわかった.1つには,多くの赤ちゃんは特別な愛着を複数の人にもつようになり,時には毎日比較的短い時間しか顔を合わさない人とでも特別な関係を築くからである.1964年に実施されたシェーファーとエマーソンによる先駆的な研究で,彼らが調べている乳児の多くは,家にいる母親だけでなく,終日仕事で外に出ている父親にも特別な愛着を抱いていることがわかった.しかし,父親に愛着を抱かない赤ちゃんもいた.さらに,ほとんどの時間いっしょにいるのは母親であるにもかかわらず,母親に(対して)ではなく,父親に愛着を抱く赤ちゃんもいた.

2 その違いは何だろうか.乳児の反応に影響を及ぼすのは親と子の社会的交流の質であることが,上記の研究でわかった.赤ちゃんは,自分たちが発している合図[信号],つまりほほ笑みやその他の顔の表情,身ぶりなどに敏感で,遊びの中で進んで自分たちとふれ合おうとする親(やほかの人たち)を特に好きになる.身の回りの世話をしてくれる人々でも自分たちと話したり遊んだりしてくれない限り,愛着をもつようにはならない.

3 親は非常に迅速に自分の赤ちゃんに愛着をもつようになるが,赤ちゃんが自身の愛着(という感情)をもつようになるには(親よりも)時間がかかる.乳児はしばしばある人といっしょにいるのを好むものだが,最初の数か月間は,たとえその特別な人がそこにいなくても,動揺することはめったにない.乳児に十分な愛着が生じるのは生後約7か月目であることを,心理学者は発見した.

4 この愛着によって親子の愛情関係の基礎が形成され,(意図的に傷つけられることがなければ)それが一生続く.そして同様に,その愛着は,親と赤ちゃんの交流の質に基づいている.人々と交わり,自分に敏感に反応してくれる人と関係を築くという生まれながらの能力は,世界中の人間の乳児に共通するものだ.それは,まさに文字どおり,人間としての遺産の一部である.