Final answer:
The hypothesis regarding smiling and laughter not serving solely to promote mating/courtship is clear and testable, as it can be empirically investigated through psychological and biological research.
Step-by-step explanation:
The hypothesis "I hypothesize that smiling and laughter do not serve to solely promote mating/courtship." is clear and testable. It suggests that there are other functions for smiling and laughter beyond mating and courtship, which could potentially be explored and examined through empirical research. Such a hypothesis would typically involve psychological and biological studies that measure various outcomes related to smiling and laughter in different social and environmental contexts. This process would help determine whether the hypothesis is supported by evidence or not.