Appeals to trust and authority: people tend to obey authorities so scammers use, and victims fall for, cues that make the offer look like a legitimate one being made by a reliable official institution or established reputable business.
Visceral triggers: scams exploit basic human desires and needs -- such as greed, fear, avoidance of physical pain, or the desire to be liked -- in order to provoke intuitive reactions and reduce the motivation of people to process the content of the scam message deeply. For example, scammers use triggers that make potential victims focus on the huge prizes or benefits on offer.
