Subject:  Contagion Bias/Negativity Bias – “One Bad Apple”

Event:  The song “One Bad Apple” hits number 1, 1971

On this day in 1971, the song “One Bad Apple” by The Osmonds hit number one on the Billboard Hot 100.  In the song, The Osmonds attempt to counter the traditional proverb “One bad apple can spoil the bunch.”  The song’s male protagonist is singing to a girl who has had a bad experience in a previous relationship.  The singer pleads with her to give him a chance:

One bad apple don’t

Spoil the whole bunch, girl

Oh, give it one more try

Before you give up on love

One Bad Apple-The Osmonds cover.jpg
Cover art for the single “One Bad Apple” (Wikipedia)

Despite the song’s attempt to rebut the proverb, research by psychologist Paul Rozin confirms the proverb’s wisdom.  In his research with cockroaches and food, he has confirmed that it takes very little of something bad to contaminate something good.  For example, after sterilizing a dead cockroach and dipping it quickly into a glass of apple juice, Rozin’s subjects refused to take a sip.  Furthermore, most of Rozin’s subjects were unwilling to drink any apple juice at all after hearing about the association of cockroaches with it — even when the apple juice was from a fresh, untainted carton.  Rozin calls this effect the contagion bias, which leads us to avoid contact with people or objects that we view as contaminated by contact with something bad.

The contagion bias is a specific phenomenon that’s a subcategory of a larger effect known as negativity bias.  In short, “Bad is stronger than good.” When it comes to the human species, negative experiences have a greater impact on us than positive ones.  In the book The Power of Bad: How the Negativity Effect Rules Us and How We Can Rule It, John Tierney and Roy F. Baumeister review research that demonstrates how, for example, we pay much more attention to criticism than we do to praise; likewise, penalties motivate us more than rewards do, and we fear losses more than we value gains.  It appears that humans are hardwired to see the glass as half empty rather than half full.

Knowledge of the contagion bias and the negativity bias is the beginning of having power over them.  Another antidote is what Tierney and Baumeister call the Rule of Four:  “It takes four good things to overcome one bad thing.”  Realize that as you go through your day, negative events will have a larger effect on you; because of this, try to maintain a realistic perspective.  Take a conscious inventory of positive things, realizing that you will need more of them to overcome the power of a single negative thing.  

For example, say you make a New Year’s resolution to exercise every day.  Be realistic enough to know that at some point you will fail, missing a day of exercise.  Instead of letting the failure overwhelm you and cause you to abandon your resolution, recognize that you are not perfect.  Employ the Rule of Four by resolving to overcome the negative feelings of failure by sticking to your exercise regimen for the next four out of five days (1).

Our negative default makes sense when you think of how our ancestors survived.  Those who cautiously lived by Murphy’s law – what can go wrong will go wrong – were the ones who survived.  In a hostile environment where you were potential prey for a hungry predator, being vigilantly on the lookout for danger was much more important than focusing on, say, a beautiful sunrise.

Another antidote to the negativity bias is to look outside yourself to find everyday wonders that you might have otherwise overlooked.  One of the best ways to look outside yourself is to go outside.  Notice, for example, how the speaker in the following poem is nudged by nature:

DUST OF SNOW by Robert Frost

The way a crow

Shook down on me

The dust of snow

From a hemlock tree

Has given my heart

A change of mood

And saved some part

Of a day I had rued.

Recall, Retrieve, Recite, Ruminate, Reflect, Reason:  What is the Rule of Four, and how does it relate to the negativity bias?

Challenge -The Glass As You See It:

The nice part about being a pessimist is that you are constantly being either proven right or pleasantly surprised. -George Will

An optimist may see a light where there is none, but why must the pessimist always run to blow it out? -Rene Descartes

Do you tend to see the glass of life as half empty or half full?  Do some research on quotations about either optimism or pessimism.  Write out the one you like the best and explain why you like it.


February 13, 1766:  British economist Thomas Robert Malthus was born on this day in 1766.  He is known for his theories regarding population growth.  In his book An Essay on the Principle of Population (1798), he said, “…nothing is so easy as to find fault with human institutions; nothing so difficult as to suggest adequate practical improvements.”


1-Tierney, John and Roy F. Baumeister. The Power of Bad: How the Negativity Effect Rules Us and How We Can Rule It. New York:  Penguin Press, 2019.