If the answer were no, the hypothesis that the ancient foragers were deliberately seeking arecoline’s effects would be much harder to sustain.

They might have been holding the nuts in their mouths for reasons unrelated to the psychoactive effect — as a food source, as something to work between the teeth out of habit, or for some other reason.

If the answer is yes — if simply sucking the nut releases physiologically significant amounts of arecoline — then the hypothesis that the foragers were seeking the drug’s effects becomes much more plausible.

The experimental approach: intact areca nuts were soaked in artificial saliva (which mimics the chemical environment of the mouth without involving human subjects) for periods consistent with the sustained nut-sucking that the dental wear implies.