1. His simple mindedness made it easy for others to trick him.
他的思想单纯，使得别人很容易欺骗他。

2. There is a certain simple mindedness in her approach to complex social issues.
她在处理复杂的社会问题时表现出某种程度的幼稚。

A: I can't believe he fell for that trick so easily.
A：真不敢相信他这么轻易就被那个圈套骗了。

B: His simple mindedness is sometimes charming, but other times it's worrying.
B：他的单纯有时很讨人喜欢，但有时也令人担忧。

1) 缺乏判断力的天真

2) 思想过于单纯而显得愚蠢

3) 对复杂事物的理解过于表面化

1. 思想单纯；愚昧

e.g.
Her simple mindedness was evident in her naive reactions.
她的天真在那些幼稚的反应中显而易见。

noun

1. The quality or state of being simple-minded; a lack of sophistication, intelligence, or judgment.

Synonym: naivety, foolishness, gullibility