The research was conducted by a couple of library researchers.
The premise of their experiment was – They were trying to determine what would make it more likely for someone to ask a librarian for help.
This effect was the same for people of all ages, races and gender.
People are much more likely to approach you when you look directly at them, than when you turn away or avoid their gaze.
For instance, nametags increased approachability for younger people way more than older people.
But still, no matter who the image depicted, they were seen as more approachable if they were wearing a nametag. They will feel like they already know something about you. So in certain professions, having a nametag may be an appropriate way to increase approachability.
Prolonged eye contact along with a smile can make all the difference to break the ice between strangers.