Most chinchillas are very very skittish and do not like to be held or petted like some other animals do.
However sometimes if and when the chinchilla gets used to their owners then they cab become very affectionate and may allow you to pet them.
However take it slow and don't scare the chinchilla and if the chinchilla doesn't want to be petted at that time don't force it and wait a few days or so and then try again.
Still some chinchillas may not like to be petted or held at all but it can depend on the individual chinchilla.
Also chinchillas are not really good pets for children because chinchillas have a high-strung disposition which makes them to not be very good pets for at least small children.
But some chinchillas may become very attached to their owners.