In a way, loss aversion is simple arithmetic. Gain is about a better future, so only dopamine is involved. The possibility of gain gets a +1 from dopamine. It gets zero from H&N, because H&N is only concerned with the present. Loss is also about the future, so it concerns dopamine, and gets a –1. Loss concerns H&N, too, because it affects things in our possession right now. So H&N gives it a –1. Put them together, and gain = +1, loss = –2, exactly what we see with the brain scans and the wagering experiments.
