David Macdonald: It's time to get out of your comfort zone

In most walks in life, the temptation to stick to what you know is strong. This tendency can save considerable time - it avoids agonising over what brand of ketchup to buy, for example, or getting lost trying to find a new route to work. Indeed, familiarity bias is a well recognised ‘heuristic' - that is, a time-saving rule of thumb to enable people to make quick decisions. Sometimes, however - and particularly with investments - it is best resisted. It is not the bias that is the problem. Everyone wants some sort of bias in their portfolio - if only to stocks that outperform. The pro...