The placebo effect is most likely attributable to a number of causes, although no one is certain what the definitive explanation might be. Some explanations for the causes of the effect include:
Research into the placebo effect is always developing and throwing new light on the phenomenon.
The difference between confirmation bias and availability bias is that they refer to two separate ways of processing information.
During World War II, early studies of damage inflicted on US bombers focused on the damage sustained by planes that made it back to their bases. The decision was made to reinforce the areas most often damaged by enemy fire.
It was soon realized, however, that this was excluding the most important sources of data—the planes that never made it back to base. It became apparent that the most important places to reinforce the craft were where they had not been hit. Because the planes that were hit there hadn’t returned.
This is an excellent historical example of survivorship bias because the planes were literally the survivors, but they lacked the most important data.
There are many types of selection bias, including:
The priming effect should not be confused with the primacy effect or primacy bias. The priming effect describes the way our brains use already-received information to help understand subsequent information.
A common example is that when primed with the word “yellow,” we process the word “banana” more quickly than the word “television,” because we associate bananas with their color.
Another example shows how a visual stimulus can prime us to hear the same sounds differently. An audio recording of the word “bob” will sound like “bob” when a video primes the listener by showing someone mouthing “bob.” However, the same audio, accompanied by the person mouthing “fob,” will be heard as “fob.”
The main interest in the priming effect is in how it helps us to understand mental processes, although it also has uses in, for example, education.
Teachers are often told to structure their lessons into three stages: tell the students what the lesson will be (the priming effect), teach the lesson, and then finally tell the students what they have just been taught (see the recency bias).
Primacy bias, or the primacy effect, is a cognitive bias (a type of mental shortcut) that gives undue prominence to information we receive early in a process (e.g., we are more likely to remember information from the beginning of a presentation than from the middle).
These mental shortcuts (also called “heuristics”) make it possible for our brains to function despite the possibly overwhelming volume of data and stimuli they have to process.
Most of the time, these heuristics work well and allow us to function. At times, though, they can introduce biases that then affect our decision-making negatively.
Anchoring bias can occur, for example, in salary negotiations or bargaining for goods such as a used car. Seeing vehicles that are out of our price range might provide a high anchor point that makes cheaper cars seem like good value, even if they are overpriced.
Anchoring bias is seen in marketing all the time with products stated as being “worth hundreds of dollars” but being offered for “only” a much cheaper price. The initial anchor of “hundreds of dollars” makes $39.99 seem like good value.
Anchoring and adjustment bias is a heuristic (mental shortcut) we use to estimate the answer to a general knowledge question. The anchor element is an initial educated guess, and it tends to limit how much we adjust our answers.
For example, if asked to estimate how long one billion seconds is, most people will underestimate the difference between one million and one billion (even though we know a billion is one thousand million).
So even if we know that a million seconds is equal to 12 days, few will correctly estimate a billion seconds correctly at 31 years.
The difference between anchoring bias and availability bias is that the former is a response to external or internal anchors that work as a starting point for estimates we form, whereas the latter favors the most recently available data.
Availability bias describes when a recent event (e.g., a plane crash) affects our assessment of how safe air travel is, because it is recent and well-publicized.
Anchoring bias can be seen in situations like purchasing a car. When we are offered, for example, a car for $20,000 that we can’t afford, that figure becomes an anchor, and a subsequent car priced at $15,000 seems cheap (even if it is objectively overpriced).
Self-serving bias is a problem for us because it hampers improvement and growth. Instead of an honest reflection and appraisal of why things have gone well or badly, we blame outside forces for our own shortcomings.
Self-serving bias is quite easily observed in real life. For example, if I am late for work, I might easily blame the traffic, a slow driver I was stuck behind, or having to wait for a passenger. If I am on time, I might congratulate myself for planning ahead and taking account of possible hold-ups. In both cases, my self-esteem is preserved.
The old saying “a bad workman always blames his tools” is another way of stating at least part of the self-serving bias. The other part is taking credit when things go well.
Both actor-observer bias and self-serving bias are types of cognitive bias. Although they both help to explain our behavior, they are quite distinct.
Self-serving bias explains how we analyze the way we have behaved, depending on whether the outcome is positive or negative. For example, if we perform well in an examination, we are likely to credit ourselves, whereas if we perform badly, we will criticize the questions, our health, or other external factors.
Actor-observer bias describes how we attribute the cause of undesirable behavior in others to their own characteristics and our own undesirable behavior to external factors. If we (the actor) are late for a meeting, we might blame the traffic or other drivers, but if someone else is late, we (the observer) blame their lack of planning or foresight.
If we cancel a planned flight because of a recent air disaster, we are demonstrating the availability heuristic. Air travel hasn’t suddenly become more dangerous (in fact, the opposite is likely to be true), but our perception of its dangers has changed.
Panic buying can be partly explained by the availability heuristic. Media coverage of panic buying can make us believe that we need to stock up on items that, in reality, we have no shortage of.
Unconscious bias is caused by several factors:
Cultural influences that promote unconscious bias are often subtle, yet pervasive (e.g., the color black being associated symbolically with evil).
There are quite a few examples of heuristics (mental shortcuts) in psychology. The availability heuristic describes how information that is more easily available to us can have a disproportionate effect on our decisions.
The representativeness heuristic leads us to believe the probability of something based on stereotypes that we carry in our minds.
Like all cognitive biases, self-fulfilling prophecies can be hard to avoid, especially because they operate at the unconscious level. There are some steps, however, that can help you avoid them:
A good example of the representativeness heuristic is a juror deciding that a person is not guilty of a crime because their appearance is very smart and ordinary. The person’s appearance does not match the juror’s perception of an “average” criminal.
The representativeness heuristic directs our focus toward superficial similarities between people and scenarios and can therefore lead to stereotyping.
Basing decisions on our stereotypes of a person’s ethnic identity, profession, or gender can lead to discrimination and bias.
Placebos are used in medical research to help establish whether a trial treatment is effective. The placebo effect describes how even receiving a “dummy” treatment (e.g., a sugar pill or saline infusion) can lead to improvement in symptoms.
For this reason, researchers use a control group who receives the placebo and a treatment group who receive the experimental drug. The effectiveness of the new treatment is measured by how much better it is at treating the condition compared with the control group.
In most cases, researchers use a double-blind experimental design to reduce bias.
Myside bias is very similar to confirmation bias (a subtype of cognitive bias), and some people use the terms interchangeably. In its specific meaning, it refers to our tendency to process information in ways that emphasize our existing beliefs. It is particularly prevalent in politics, but can also be seen in sports.
For example, a possible infraction in a soccer game will be seen as an obvious foul by one group of fans, but not by the other group of fans.
Cognitive bias is very difficult to spot in our own thinking, but there are some things to watch out for if we want to maintain intellectual integrity.
Attention bias is a cognitive bias that affects how we perceive the world around us. We cannot process all the information our senses provide us with, so we filter them out.
Attention bias can have positive and negative impacts. For example, when hiking in the wilderness, we might be more attuned to spotting snakes or other dangerous wildlife.
On the other hand, if we are on a diet, we might find ourselves drawn to the dessert section of the menu at a restaurant.
Both explicit bias and unconscious bias involve prejudiced attitudes that can lead to discriminatory actions and decisions.
They differ in a few essential respects:
When people claim to be unbiased, they typically have explicit biases in mind, unaware that they have unconscious biases.
Unconscious bias can have several adverse effects in the workplace:
These can be mitigated by raising awareness through strategies like implicit bias testing, setting objective criteria for performance reviews, and adopting blind hiring processes.