I think all kids should have the chance to create sculpture. However, sculpture can be a real mess and there are lots of parents out there who'd rather just avoid sculpture activities altogether. I know parents who don't even like their kids to play with Play Dough! But such tactile activities are important for kids' brain development, plus....it's fun.
I found a sculpture activity that has very little mess or clean up that is great for all ages...which is always the sign of a good activity for our house.
Pour 1/2 cup of powdered plaster in a ziploc bag. Add to that 1/4 cup of warm water. If you have bigger kids you may want to double the quantities. Squeeze the air out of the baggie and seal it tightly. Put the first baggie into another baggie and squeeze all the air out again and seal. Double bagging prevents a mess from a busted bag.
Then the kids do the rest. The water and plaster need to be squeezed and worked together until it is smooth inside the bag. The plaster can be worked for 20 minutes or so before it begins to thicken. Then the plaster can be 'shaped' and poked.
A lot of kids probably won't have the attention span to play with their plaster for 20 minutes straight but remind them to check it occasionally. After the plaster begins to harden remind them that they need to leave it alone so it doesn't turn into a crumbly mess. As it hardens they can feel how the plaster heats up as it sets.
Leave the plaster to sit overnight and remove the baggies in the morning.
The creases from the bags may show up.
The plaster sculpture can be left alone or painted with craft paint.
A great tactile experience with very little mess.