Attentional Bias

Our attention is a finite resource: there are limits to how much we can attend to at any given time. In order to make rational decisions, ideally, we would want to consider all of our options and examine them each in turn. When attentional bias shows up, however, we end up directing a much larger share of our focus toward a single option or stimulus, and this comes at the expense of others. It can also make it more difficult for us to let go of distracting or unhelpful thoughts, causing us instead to fixate on (and overthink) certain things.

Attentional bias carries implications for many institutions. One important example pertains to law enforcement. One study demonstrated that police officers who were experiencing high levels of anxiety were more likely to shoot at suspects during a training exercise,¹ suggesting that anxiety biased the officers to narrowly focus on threat-related information.

Attentional bias is also highly relevant to racial profiling and prejudice in policing. In our culture, Black people, particularly young men, are frequently and erroneously depicted as dangerous criminals. This image is so ubiquitous that many individuals, including police officers, implicitly associate Black faces with crime.^{2, 3} This results in a biasing of attention towards Black people, and overanalyzing normal behaviours as “suspicious” when they are being carried out by a Black person.

Individuals struggling with a substance use disorder may also be negatively impacted by attentional bias. Drug dependence produces an attentional bias for the drug in question, causing addicted individuals to fixate on stimuli related to the substance in question.⁵ Moreover, one study that followed heroin addicts as they embarked on a treatment program found that attentional bias was predictive of relapse: the more participants exhibited heroin-related attention bias before starting treatment, the more likely they were to have relapsed by the 3-month mark.⁶ This underscores the importance, in rehabilitation, of removing any drug-related stimuli from one’s day-to-day environment.

In part, attentional bias is just a consequence of our limited cognitive abilities as humans. As mentioned above, we have a finite capacity for attention; as much as we try to convince ourselves otherwise, we can really only focus on a small number of things at a time. There are various evolutionary and cognitive explanations for why certain things consistently bias our attention.

Biased attention carries evolutionary advantages

Although attentional bias can lead to flawed reasoning and unbalanced decision making, in prehistoric times, it is likely that certain biases resulted in behaviour that facilitated survival. One important example is our bias to focus on food. Research suggests that the human attentional system is tuned to attend more to food than nonfood items.⁷ Hunger amplifies this effect through attentional bias.⁴

Similarly, although modern research has linked attentional bias for threatening information to clinical anxiety disorders,⁸ in the past, being vigilant and responsive to potential dangers in one’s environment could actually have been the difference between life and death. Individuals who had these traits were probably more likely to survive and pass on their genes, letting these biases proliferate throughout our species.

Importantly, attentional biases that proved to be an advantage in the ancient past may not be advantageous today. Our environment has changed profoundly: for most people, food is available in abundance, and we no longer have to worry about guarding the village from sabertooth tigers. But our brains retain the hardwiring that benefited our ancestors, even if it is no longer appropriate.

We attend to information consistent with our schemas

Our brains rely on many shortcuts and rules of thumb to speed up processing and help us navigate the world. Schemas, or frameworks that help us organize and sort information, are one type of shortcut. We have schemas for virtually everything we encounter in our day-to-day life, from people we meet to situations we encounter. As an example, your schema for your friend Julie might include information such as “tall,” “plays hockey,” and “hates spicy food.”

The majority of the time, schemas are useful tools that our brains use to sort through the massive amount of information it must process every day. However, they can also facilitate attentional bias: people are more likely to attend to information that matches up with their existing schemas, and to ignore information that does not. People with depression, for instance, tend to have schemas that are negative about themselves and the world,11 and are also biased to attend to negative information over positive information.12 By contrast, people not experiencing depression are generally biased towards positivity.

In our personal and professional lives, attentional bias can give us tunnel vision, overemphasizing some factors and blinding us to others. When we narrowly focus on one or two things, we end up overthinking them, and assigning them greater importance in our decision making than we should. For example, company executives might focus too much on a particular measurement of their employees’ productivity, and end up ignoring other valuable indicators of performances. Other times, a bias toward emotional information might cause us to make decisions without more objective sources of data.

It is difficult to completely avoid attentional bias. Often, the influence of this type of bias on our thinking is at such a deep, automatic level that we are not aware it is happening.

Feedback and practice

In some cases, it appears that it is possible to reduce the effects of attentional biases through training. For instance, depressed participants can be trained to focus more on positive stimuli.¹² However, in this context, study participants were not merely practicing on their own; instead, they were receiving feedback from the researchers that reinforced focus on positive stimuli and discouraged focus on the negative. To apply this in the real world, if there is a specific type of attentional bias one is looking to avoid, it might help to enlist a friend or family member who can point out moments you fall into biased thinking, and offer reminders to zoom out.

For individuals suffering from depression or anxiety, some treatments, such as cognitive behaviour therapy (CBT), involve examining attentional bias and learning strategies to challenge it. This is often done using worksheets, where the client recounts an upsetting situation and explores the role that attentional bias might have played in how they interpreted it.

Plan around bias pitfalls

For some types of attentional bias, it is often possible to plan in a way that minimizes the risk of that bias arising. Remember our hypothetical trip to the grocery store? Scheduling your food shopping for sometime one is not likely to be hungry—after dinner, for example—will likely reduce attentional bias for unhealthy items, making it easier to avoid them.

Try some mindfulness exercises

In recent years, mindfulness meditation is often prescribed as a tool to boost attention and improve productivity. As much as it has become a buzzword, there is actually empirical evidence to support the effectiveness of mindfulness practice—including as a tool to reduce attentional bias.

In one study, researchers compared attentional bias in experienced meditators versus non-meditators. The participants were shown images of both neutral and emotional faces, and their eye movements were tracked. The results showed that meditators spent significantly less time looking at angry and fearful faces. What’s more, while non-meditators showed attentional bias for both angry and happy faces, meditators only showed this effect for happy faces.

This experiment suggests that, over time, getting into the habit of mindfulness meditation can minimize certain kinds of attentional bias. One caveat: the meditators in this study had been practicing mindfulness, on average, for over twelve years—not a commitment most of us are willing or able to make. Luckily, other research has found that even shorter mindfulness programs can help reduce attentional bias.¹⁷

One of the most popular tests for attentional bias originated with an American psychologist named John Ridley Stroop. In 1935, Stroop conducted a now-famous experiment, wherein he presented participants with the names of colors written in various colors of ink. Each word belonged to one of 3 groups: neutral (written in black ink), congruent (the color name matched the color of the ink), or incongruent (the color name did not match the color of the ink). Participants were asked to simply read the written color name aloud, ignoring the color of the ink. It was found that people were slower to name the color when the name and ink colors were incongruent. This paradigm is now known as the Stroop Task.

A modified version of the Stroop task, known as the Emotional Stroop (ES) Task, became widespread in the 1980s.14 In this version, instead of reading color names, participants were told to say aloud the color in which each word was written. Additionally, all the words were grouped according to their emotional value: neutral (e.g. “tree”), positive (e.g. “holiday”), or negative (e.g. “hatred”).¹⁵ Slower reaction times were interpreted to mean that deeper processing of a given word was taking place, suggesting a possible attentional bias.

Numerous variations of the ES were conducted in this period, testing patients a wide range of groups. It was these studies that first established certain attentional biases that are now well-known. For example, Gotlib and McCann (1984) found that depressed participants were slower to name the colors of negative words; in Mathews and MacLeod (1985), anxious patients were slower for threatening words, particularly words that were related to an individual’s particular fears; and Watts et al. (1986) showed that arachnophobes were delayed when reading spider-related words.¹⁴ 

People who smoke tobacco are known to have attentional bias for cigarettes and other smoking-related cues. An adapted version of the Stroop task provides empirical evidence of this: smokers, in comparison to non-smokers, are slower to color-name smoking-related words versus neutral words.¹⁸

For smokers who decide to quit, this can be a major stumbling block, causing them to fixate on objects or situate that they associate with smoking. Attentional bias leads smokers to direct more of their mental energy towards thinking about and processing smoking-related cues, which in turn increases the craving for tobacco. Furthermore, anything that the individual has associated with cigarette smoking in their own life could potentially trigger this preoccupation, including stimuli and situations that aren’t strictly related to tobacco—for example, the cup of coffee that would normally be accompanied by a cigarette.

Our political ideologies have obviously shaped our knowledge about the world. However, what information we pay attention to and remember is subject to bias. Research even suggests that selective attentional bias in conservatives and liberals might contribute to differences in political beliefs.

In one study, researchers had students of different political affiliations complete the Emotional Stroop Task, as well as other measures of attentional bias. The results showed that liberals were biased to focus on words with emotionally positive content, while conservatives focused more on the negative.¹⁹ This may indicate that our differences in beliefs may stem from very basic attentional processes, automatically filtering out separate kinds of information and orienting us towards different sets of data.

What it is

Attentional bias describes how we often direct our attention more to some things than others. When we are making decisions, this can cause us to fixate on a small subset of data points and ignore the rest.

Why it happens

Our attention is a finite resource; focusing on one thing comes at the expense of others. Faced with a massive amount of incoming information every second, our brains are constantly trying to figure out what is most worthy of our concentration. Some stimuli that tend to bias our attention, such as hunger and anxiety, likely have evolutionary roots. Other times, our attention can be biased by cognitive schemas that we have acquired over the course of our lives.

Example 1 - Why attentional bias makes it harder to quit smoking

When trying to quit smoking, reminders of cigarettes and tobacco can contribute to cravings, and eventually to relapse. This is largely because ex-smokers have attentional bias for tobacco-related cues, which causes them to process these cues more deeply than a non-smoker would.

Example 2 - How attentional bias contributes to differences in political beliefs

Attentional bias may contribute to different political beliefs by causing people to selectively focus on different kinds of information. Conservatives have an attentional bias for words with negative emotional content, while liberals are biased towards positive emotional content.

How to avoid it

Because attentional bias takes place at a very basic, automatic level of cognition, it is difficult to avoid it altogether. In some cases, it may be possible to plan around possible triggers of bias. Feedback and practice can also decrease attentional bias, as can mindfulness practice.