此句句意為雖然在接觸中很容易忽視我們的行為對(duì)他們性格的影響,但是在和成年人的交往中忽視這種影響并不容易.
While it is easy to ignore in our contact with them the effect of our acts upon their disposition, it is not so easy as（to ignore in our contact with them the effect of our acts upon their disposition） in dealing with adults.太羅嗦,所以要省略
to ignore the effect of our acts upon their disposition這是一件事,暫以to do sth代替
則原句可簡(jiǎn)化為While it is easy to do sth in our contact, it is not so easy as( to do sth) in dealing with adults
多讀幾遍,其義自現(xiàn),不知你是否理解了,若還不理解,還可追問(wèn)從中文翻譯中，就知道省略的是這個(gè)effect