I know it may sound unreasonable but I don't like my 6mth old sucking her fingers or her thumb. I also don't give her a dummy. My reason being I know too many people who told me they still did it well into their teenage years and my sister in law who is in her 30s still does it on occasion. Has anyone any ideas?
I'm not sure you should be too worried. I think the examples you have in mind are on the extreme end of thumbsucking. Babies are very oral until toddlerhood anyway, some even beyond. Most young children can be persuaded to give it up eventually, if they don't do so spontaneously when they find they can't suck a thumb and play with their toys at the same time. Some revert to it when they're bored or stressed -- maybe this self-calming is not such a bad thing?