Question

楓

下から4行目のIn one set of studies からの訳がイマイチ分かりません。一文ごとには訳せているつもりなのですが大まかに解説して頂きたいです。

C But what exactly is beauty? Trying to define it is difficult, and yet we know it when we
see it-or so we think. "Beauty is health," says one psychologist. "It's a billboard saying.
Tm healthy. I can pass on your genes." And our awareness of it may start at a very early
age. In one set of studies, six-month-old babies were shown a series of photographs.
The faces in the pictures had been rated for attractiveness by a group of college students.
In the studies, the babies spent more time looking at the attractive faces than the