If there's a group, responsibility to help decreases and this is captured in different ways but the main idea is we all think someone else will help so we don't. There's a diffusion.

如果是一群人，帮助的责任就会分散变小,这体现在多个方面,但最主要的想法就是我们都认为别人会帮助,所以我们就不帮助了，责任被分散了。

耶鲁公开课 - 心理学导论课程节选

His main line is sold in over 50 countries worldwide, along with his diffusion lines RC Menswear and Just Cavalli, plus a children's line, knitwear, accessories, eyewear, watches, perfumes, underwear and beachwear.

CNN: Fashion's peacock: Designer Roberto Cavalli