Negativity Bias And Financial Markets

Negativity Bias is one of the powerful and ineradicable aspects of human psychology, which has important effects on the performance of stock market investors

Negativity Bias is perhaps the most expensive and dangerous item in our psychological repertoire insofar as it impacts on our performance in financial markets.  In this post, I will outline the bias and then discuss how its effects play out in markets.

Negativity Bias is reflected in the finding that negative events affect us much more strongly than positive ones.  I should immediately distinguish this effect from the bias I was discussing in my previous post (  There, I discussed the subset of Attentional Biases that operate in people who are depressed or anxious, such that they pay more attention to mood congruent information.  Negativity Bias differs from that in that it affects everyone, irrespective of mood and psychiatric diagnosis.  Some forms of Attentional Bias do that as well, but in the previous post I considered only mood-related variants thereof.

The bias can be seen as a mis-calibration, like many of our cognitive biases.  There is a “right-size” for the amount of impact that an event should have on us which is related to the “intensity” of that event.  Obviously, intensity is rather a slippery concept here, but we can give some meaning to it with illustrations.  Two negative events of different intensities would be stubbing one’s toe and breaking an arm.  Two positive events with differing intensities would be receiving a birthday card or falling in love.

So without Negativity Bias — and with what we might regard as a purely rational response to events — there would be a link between the intensity of an event and its impact upon us.  There would not be a link between whether the event  was positive or negative and the size of the impact of the event on us.  This does not mean that it is strange that we react negatively to negative events and positively to positive events (in fact, it would be very strange were this not so!).  What it means is that it is odd that we react more strongly to negative events than we do to positive events of the same intensity.

This was measured by experimental social psychologists in financial terms using sums of money.  It was found that the mis-calibration is very strong: the factor is about 2.5.  In other words, we react 2.5x as strongly to losing $10 as we do to gaining $10.  In other other words, losing something is much, much worse than gaining the same amount.

The Negativity Bias then will have huge impacts on our risk aversion, and that, it is well known, is a key driver of performance in financial markets.  Many people perform extremely badly as a result of excess risk aversion.  In the current environment, it is unwise to be holding substantial amounts of cash.  People should have some emergency funds of course.  But if CPI is running at 3% and interest rates paid by the banks are more like 1%, then anyone holding cash in the bank is basically prepared to pay 2% a year in order to avoid any risk, as they see it.

As I see it, paying to avoid risk like this is just concretising the risk.  You don’t gain: you just get the loss in a form you can pretend doesn’t exist.  It would be much better — and in fact less risky understood correctly — to invest in something.  There is an enormous spectrum of assets and geographies out there from equities in the US, Japan, Emerging Markets and Frontier Markets to bonds issues by governments, investment grade corporates and junk corporates.  There are thousands of ETFs available offering the widest imaginable range of exposures.  Overcome your Negativity Bias and pick one.

I discuss in much more detail the important effects in financial markets of Cognitive Biases like Negativity Bias in my new book:

If you want to discuss these and other concepts mentioned in the book, or for more information about the book, you can Send Mail