Humans Biologically Disposed To Help

In his new book Why We Cooperate, Dr. Michael Tomasello writes that 18-month-old infants will attempt to help when they see an unrelated adult whose hands are full trying to open a door or pick up a clothespin. What do you think?

"Dr. Tomasello shouldn't jump to conclusions about 'human' biology. An 18-month-old may try to pick up your clothespin, but the 18-year-old will point at you and laugh for being poor and using a clothespin."