This is Hidden Brain, I'm Shankar Vedantu. We begin today's show in a snowy Midwestern

school yard. A group of boys is gathered around a flat pole. One is daring the other to

stick his tongue to the icy metal. If you've seen the film a Christmas story, you know

where this is headed. The double dog dare escalates to a triple dog dare, which ends, no surprise

here with a boy's tongue stuck to a flat pole. Okay, that's just the movies. Many of us

like to think we'd never succumb to this sort of peer pressure. We believe we are independent

thinkers that our choices are our own. Our values and preferences are inherent to our personalities,

not the whims and wishes of others. It turns out though that reality is a bit more complicated.

Everywhere in life, at work at school, at a sports game in a big stadium with thousands

of other people at home in the privacy of our own bedrooms, our behavior is constantly

shaped by the judgements, norms and actions of other people. Sometimes we can feel this

influence, such as when our tongue is stuck to an icy flat pole. But more often than not,

these influences are so subtle we don't even notice their existence. My guest today has

spent a lot of time thinking about these forces that act on us.

Jonah Berger is a marketing professor at the University of Pennsylvania and the author

of the book Invisible Influence, the Hidden Forces that shape behavior.

Jonah, welcome to Hidden Brain. Thanks so much for having me.

These often pay celebrities to hawk their merchandise, so I often see athletes wearing

clothes with a Nike swoosh. Tiffany apparently once paid Anne Hathaway $750,000 to wear its

jewelry at the Oscars. But a few years ago, you tell the story of how Abacrame and Fitch

made an unusual offer to the stars of Jersey Shore. What was that offer?

So you may remember the Jersey Shore, sort of a bunch of early 20s folks, lots of fake

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