^Life is stressful, right from birth. That's why babies cry.
Thumb sucking is a stress response, creating a feedback loop that says, "I'm still here and everything is ok as long as I'm still here."
(that's my interpretation)
Studies with rats in cages have shown that stress responses can be reduced to zero when they're in what's called "enriched environments" Plenty of food, water, space, diversions, few restrictions on behavior.
There's needs to be more play and less structure. There. That's how I'd change the world.
…just keep the knives, fire and drainplugs away. Oh and things with lids and hinges and heavy things balanced on unstable shelves… oh and soften hard surfaces…
Great.. I've just advocated rubber rooms for all.
Oh wait – then you have latex allergies… dang it. Hm, Plastics! Oh, but the environment… and volitile organic compounds…
Ugh. Just keep a stack of bandaids, an Epipen and some sticks and wraps for broken bones. There. Solved. Sort of…. not really.^