What if a sustainability-minded person is in the in-group, and a less convinced citizen/consumer is in the out-group? It can seem that ne'er the twain shall meet. What could they possibly have in common?
My initial hypothesis was that talkers are socially conditioned. The 'talking gene' must be related to other traits like aggressiveness, openness, and friendliness; and that this is contingent upon a child's behavior.