Reference

If you think about it, there are people in any society whose behaviour is, in effect, totally individualistic – they make no reference to the needs of others. However, such people are invariably labelled "mad" or "insane", precisely because others find it impossible to interact socially with such people.

On a less serious level, very young children also, on many occasions, act individualistically (that is, without thought for others or the consequences of their behaviour). This is because such children have not learnt to act in a fully-social manner (their socialisation into the basic norms of society is incomplete).