Sociability is the quality of being sociable — of liking to be with other people, and being easy and friendly when you are. It is the noun for that side of a person. You use it when you talk about the quality itself, not about one friendly act: 'Her sociability made her popular at work' means being-friendly-with-people is a thing she has, all the time, not just that day. It is a slightly formal word. In everyday talk a Taiwanese student is much more likely to hear 'she's very sociable' or 'she's a people person' than 'her sociability'. Where you really do meet the noun is in writing — psychology, education reports, book reviews, articles about children or about animals. Teachers write it on reports: 'good sociability with classmates'. And it stretches in two useful ways. It can be used of animals — dogs, monkeys, and bees are said to have sociability, meaning they naturally live in groups. And it can be used of a place or an event rather than a person: 'the sociability of the old market' means the market was a place where people mixed and talked easily. Notice one thing carefully: sociability is about wanting company and being comfortable in it. It is not about being kind, and it is not about being good at company. A quiet person can be very warm and have little sociability; a loud person can have plenty of sociability and still be rude.

善於社交（的特質）、合群、愛交際。中文常用形容詞說「他很好相處」「他很會社交」；名詞形式在中文寫作、心理學或學生評語裡才常見（如「社交性」）。注意別直接想成「人緣好」——人緣好是別人喜歡你的結果，sociability 是你自己喜歡跟人相處的性格。