Smile at so-and-so and then that's augmently run with social pressure in their life. If you don't smile at someone, even if they don't smile back at the checkout counter person who's saying, "Have a nice day," "have a nice day" like a robot, these are social niceties you might say, but it's expectations as well. If you don't smile back then you're antisocial.
Tabasamu na huyu au huyu hiyo inafanyishwa na msukumo wa kijamii. Usipotabasamu na mtu, hata wasipotabasamu na wewe kama wafanyikazi kwa maduka kubwa wanayesema,”kuwa na siku mzuri”, kuwa na siku mzuri” kama mashine hizi ni vitu za kijamii lakini matarajio pia. Usipowatabasamia wewe si mtu wa kijamii.