We randomly selected 806 children under 6 years of age from 45 primary anganwadi (childcare) centres in Chandigarh, Punjab, India, that were chosen through multistage stratified random sampling.
Scientists believe the existence of this age-old reward mechanism indicates there is an evolutionary advantage in sampling the unknown.
科学家认为，脑部这种古老的奖励机制在尝试未知事物方面有进化优势。
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Methods Questionnaire survey was conducted among 1298 residents sampled by randomly stratified sampling. The age of the residents ranged from 15 to 69 years old.