We all want to do good - and doing good can make us feel good - but we often don't make the most effective choices when we do things like donate money to charity.

To mark #GiveTuesday, Harvard psychologist Joshua Green explains why we tend to give with our hearts rather than our heads. And why this means we don't do the most good possible with every dollar we donate.

To donate to some of the most effective charities around (and to the causes close to your heart) go to: https://givingmultiplier.org/HAPPINESSLAB