Match each everyday observation to the factor that explains it.

• You come to like a song you first found irritating, after hearing it daily for a month → Mere exposure effect
• You warm to a colleague immediately after learning that he speaks well of you → Reciprocity of liking
• An attractive stranger is assumed to be kind and clever before saying a word → The 'what is beautiful is good' stereotype
• Most of your close friendships began with people whose desks or doors were nearest to yours → Proximity

Repetition raising liking for a song is mere exposure in its purest form; nearness generating friendships is proximity, which works largely through that same exposure; learning someone likes you is reciprocity; and inferring kindness from looks is the beauty halo. Keeping proximity and mere exposure distinct matters - proximity is the circumstance, exposure is the mechanism.