sentences: increasing the availability of something that has a positive impact on a living thing's survivial can have a positive impact on that living thing's survival
docs: pleasantness is pleasure. kindness is good. music is what_makes_life_wonderful_sometimes. cheerfulness is happiness. one_thing_makes_people_happy is having_hobby. spouse has effect_of_happiness telling_joke has effect_of_making_people_laugh one_step_to_good_attitude is create_happiness_for_other_people. delight is cheerfulness.