His constant need for attention at work is seen as rather childish.

childish 是由名词 child（孩子）加上形容词后缀 -ish 构成的形容词。-ish 表示"具有...特征的"，childish 字面意思是"像孩子一样的"，引申为"幼稚的、孩子气的"，常带有贬义，指行为举止不够成熟。