14.心理学家认为有些人常以为有人在后面看他们,其实是当他们认为有人看他们的时候,他们会turn their heads and that this action will attract attention from nearby people to look at them。所以人以为有人在后面看他们并不是真的,问evaluate
when there are someone behind them, as well as when no one behind them, how frequent will they turn their heads