One friend tells you to change your shirt. Another friend says, "You know that green shirt you have? You look great in that shirt." Who's more convincing? If you're reaching for that green shirt, you've been affected by Nudge theory. According to this concept, subtle suggestions are much more effective at influencing behavior than direct instruction. For example, telling someone to reduce their energy consumption would be less effective than showing them that their energy consumption is much higher than their neighbors'. The idea behind this theory is that direct instruction can be met with frustration, and could prompt someone to behave in a way that is the opposite of what was intended.
Proponents of direct communication say that "nudging" is mental manipulation. Is it unethical? As reported by The Guardian, "tiny tweaks [nudges] in government communication may increase the success rates of ethnic minority applicants to join the police; can help people to take vital medications; or pay their taxes on time." But what about tricksters using nudges for selfish reasons? For example, if you give someone a larger bowl and larger spoon, they will eat more ice cream, according to a study. While that's in the best interest of ice cream sellers, it's not quite the best thing for your health.