The Curd Rice...
Curd Rice is the only Indian food which releases a Chemical called Tryptophan in Brain. Indians alone take Curd as Curd. But western world takes it as Yogurt, which has got Sugar too, and sugar will not calm your Brain, but increase Glucose level and will put one to more restlessness. Sugar is dangerous for the Balance of Neural activity. It triggers hyperactivity.
But Curd rice is the only food which can release Tryptophan in Brain, which calms down and brings a cool thinking, and your neurons are recharged with a mild rest because of Tryptophan. ( In Sanskrit there's a word for this Chemical, as Thrupthophan, Thrupthi means Satisfaction).
Curd rice is the Scientific reason for the success of Many Indians, as it the Best brain food which activates the Brain in a balanced manner for a Tropical climate!