Did the data from the Cal and Stanford games somehow get left out?
Anchoring From Wikipedia, the free encyclopedia
Anchoring or focalism is a cognitive bias where an individual depends too heavily on an initial piece of information offered (considered to be the "anchor") when making decisions.
Anchoring occurs when, during decision making, an individual depends on an initial piece of information to make subsequent judgments. Those objects near the anchor tend to be assimilated toward it and those further away tend to be displaced in the other direction. Once the value of this anchor is set, all future negotiations, arguments, estimates, etc. are discussed in relation to the anchor. This bias occurs when interpreting future information using this anchor. For example, the initial price offered for a used car, set either before or at the start of negotiations, sets an arbitrary focal point for all following discussions. Prices discussed in negotiations that are lower than the anchor may seem reasonable, perhaps even cheap to the buyer, even if said prices are still relatively higher than the actual market value of the car.[1]
The original description of the anchoring effect came from psychophysics. When judging stimuli along a continuum, it was noticed that the first and last stimuli were used to compare the other stimuli (this is also referred to as "end anchoring". This was applied to attitudes by Sherif et al. in 1958 in their article "Assimilation and contrast effects of anchoring stimuli on judgments". Contents
1 Adjustment heuristic 1.1 Difficulty of avoiding 2 Causes 2.1 Anchoring-and-adjusting 2.2 Selective accessibility 2.3 Attitude change 3 Influencing factors 3.1 Mood 3.2 Experience 3.3 Personality 3.4 Cognitive ability 4 In negotiations 5 See also 6 References 7 Further reading
Adjustment heuristic
Anchoring and adjustment is a psychological heuristic that influences the way people intuitively assess probabilities. According to this heuristic, people start with an implicitly suggested reference point (the "anchor") and make adjustments to it to reach their estimate. A person begins with a first approximation (anchor) and then makes incremental adjustments based on additional information. These adjustments are usually insufficient, giving the initial anchor a great deal of influence over future assessments. Daniel Kahneman, one of the first researchers to study anchoring.
The anchoring and adjustment heuristic was first theorized by Amos Tversky and Daniel Kahneman. In one of their first studies, participants were asked to compute, within 5 seconds, the product of the numbers one through eight, either as 1 × 2 × 3 × 4 × 5 × 6 × 7 × 8 {\displaystyle 1\times 2\times 3\times 4\times 5\times 6\times 7\times 8} 1 \times 2 \times 3 \times 4 \times 5 \times 6 \times 7 \times 8 or reversed as 8 × 7 × 6 × 5 × 4 × 3 × 2 × 1 {\displaystyle 8\times 7\times 6\times 5\times 4\times 3\times 2\times 1} 8 \times 7 \times 6 \times 5 \times 4 \times 3 \times 2 \times 1. Because participants did not have enough time to calculate the full answer, they had to make an estimate after their first few multiplications. When these first multiplications gave a small answer – because the sequence started with small numbers – the median estimate was 512; when the sequence started with the larger numbers, the median estimate was 2,250. (The correct answer is 40,320.) In another study by Tversky and Kahneman, participants observed a roulette wheel that was predetermined to stop on either 10 or 65. Participants were then asked to guess the percentage of the United Nations that were African nations. Participants whose wheel stopped on 10 guessed lower values (25% on average) than participants whose wheel stopped at 65 (45% on average).[2] The pattern has held in other experiments for a wide variety of different subjects of estimation.
As a second example, in a study by Dan Ariely, an audience is first asked to write the last two digits of their social security number and consider whether they would pay this number of dollars for items whose value they did not know, such as wine, chocolate and computer equipment. They were then asked to bid for these items, with the result that the audience members with higher two-digit numbers would submit bids that were between 60 percent and 120 percent higher than those with the lower social security numbers, which had become their anchor.[3] Difficulty of avoiding
Various studies have shown that anchoring is very difficult to avoid. For example, in one study students were given anchors that were obviously wrong. They were asked whether Mahatma Gandhi died before or after age 9, or before or after age 140. Clearly neither of these anchors can be correct, but when the two groups were asked to suggest when they thought he had died, they guessed significantly differently (average age of 50 vs. average age of 67).[4]
Other studies have tried to eliminate anchoring much more directly. In a study exploring the causes and properties of anchoring, participants were exposed to an anchor and asked to guess how many physicians were listed in the local phone book. In addition, they were explicitly informed that anchoring would "contaminate" their responses, and that they should do their best to correct for that. A control group received no anchor and no explanation. Regardless of how they were informed and whether they were informed correctly, all of the experimental groups reported higher estimates than the control group. Thus, despite being expressly aware of the anchoring effect, participants were still unable to avoid it.[5] A later study found that even when offered monetary incentives, people are unable to effectively adjust from an anchor.[6] Causes
Several theories have been put forth to explain what causes anchoring, and although some explanations are more popular than others, there is no consensus as to which is best.[7] In a study on possible causes of anchoring, two authors described anchoring as easy to demonstrate, but hard to explain.[4] At least one group of researchers has argued that multiple causes are at play, and that what is called "anchoring" is actually several different effects.[8] Anchoring-and-adjusting
In their original study, Tversky and Kahneman put forth a view later termed anchoring-as-adjustment. According to this theory, once an anchor is set, people adjust away from it to get to their final answer; however, they adjust insufficiently, resulting in their final guess being closer to the anchor than it would be otherwise.[9] Other researchers also found evidence supporting the anchoring-and-adjusting explanation.[10]
However, later researchers criticized this model, because it is only applicable when the initial anchor is outside the range of acceptable answers. To use an earlier example, since Mahatma Gandhi obviously did not die at age 9, then people will adjust from there. If a reasonable number were given, though, there would be no adjustment. Therefore, this theory cannot, according to its critics, explain the anchoring effect.[11]
Another study found that the anchoring effect holds even when the anchor is subliminal. According to Tversky and Kahneman's theory, this is impossible, since anchoring is only the result of conscious adjustment.[12] Because of arguments like these, anchoring-and-adjusting has fallen out of favor.[citation needed] Selective accessibility
In the same study that criticized anchoring-and-adjusting, the authors proposed an alternate explanation regarding selective accessibility, which is derived from a theory called "confirmatory hypothesis testing". In short, selective accessibility proposes that when given an anchor, a judge (i.e. a person making some judgment) will evaluate the hypothesis that the anchor is a suitable answer. Assuming it is not, the judge moves on to another guess, but not before accessing all the relevant attributes of the anchor itself. Then, when evaluating the new answer, the judge looks for ways in which it is similar to the anchor, resulting in the anchoring effect.[11] Various studies have found empirical support for this hypothesis.[13] This explanation assumes that the judge considers the anchor to be a plausible value so that it is not immediately rejected, which would preclude considering its relevant attributes.[citation needed] Attitude change
More recently, a third explanation of anchoring has been proposed concerning attitude change. According to this theory, providing an anchor changes someone's attitudes to be more favorable to the particular attributes of that anchor, biasing future answers to have similar characteristics as the anchor. Leading proponents of this theory consider it to be an alternate explanation in line with prior research on anchoring-and-adjusting and selective accessibility.[14][15] Influencing factors Mood
A wide range of research has linked sad or depressed moods with more extensive and accurate evaluation of problems.[16] As a result of this, earlier studies hypothesized that people with more depressed moods would tend to use anchoring less than those with happier moods. However, more recent studies have shown the opposite effect: sad people are more likely to use anchoring than people with happy or neutral mood.[17]
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From Wikipedia, the free encyclopedia
Anchoring or focalism is a cognitive bias where an individual depends too heavily on an initial piece of information offered (considered to be the "anchor") when making decisions.
Anchoring occurs when, during decision making, an individual depends on an initial piece of information to make subsequent judgments. Those objects near the anchor tend to be assimilated toward it and those further away tend to be displaced in the other direction. Once the value of this anchor is set, all future negotiations, arguments, estimates, etc. are discussed in relation to the anchor. This bias occurs when interpreting future information using this anchor. For example, the initial price offered for a used car, set either before or at the start of negotiations, sets an arbitrary focal point for all following discussions. Prices discussed in negotiations that are lower than the anchor may seem reasonable, perhaps even cheap to the buyer, even if said prices are still relatively higher than the actual market value of the car.[1]
The original description of the anchoring effect came from psychophysics. When judging stimuli along a continuum, it was noticed that the first and last stimuli were used to compare the other stimuli (this is also referred to as "end anchoring". This was applied to attitudes by Sherif et al. in 1958 in their article "Assimilation and contrast effects of anchoring stimuli on judgments".
Contents
1 Adjustment heuristic
1.1 Difficulty of avoiding
2 Causes
2.1 Anchoring-and-adjusting
2.2 Selective accessibility
2.3 Attitude change
3 Influencing factors
3.1 Mood
3.2 Experience
3.3 Personality
3.4 Cognitive ability
4 In negotiations
5 See also
6 References
7 Further reading
Adjustment heuristic
Anchoring and adjustment is a psychological heuristic that influences the way people intuitively assess probabilities. According to this heuristic, people start with an implicitly suggested reference point (the "anchor") and make adjustments to it to reach their estimate. A person begins with a first approximation (anchor) and then makes incremental adjustments based on additional information. These adjustments are usually insufficient, giving the initial anchor a great deal of influence over future assessments.
Daniel Kahneman, one of the first researchers to study anchoring.
The anchoring and adjustment heuristic was first theorized by Amos Tversky and Daniel Kahneman. In one of their first studies, participants were asked to compute, within 5 seconds, the product of the numbers one through eight, either as 1 × 2 × 3 × 4 × 5 × 6 × 7 × 8 {\displaystyle 1\times 2\times 3\times 4\times 5\times 6\times 7\times 8} 1 \times 2 \times 3 \times 4 \times 5 \times 6 \times 7 \times 8 or reversed as 8 × 7 × 6 × 5 × 4 × 3 × 2 × 1 {\displaystyle 8\times 7\times 6\times 5\times 4\times 3\times 2\times 1} 8 \times 7 \times 6 \times 5 \times 4 \times 3 \times 2 \times 1. Because participants did not have enough time to calculate the full answer, they had to make an estimate after their first few multiplications. When these first multiplications gave a small answer – because the sequence started with small numbers – the median estimate was 512; when the sequence started with the larger numbers, the median estimate was 2,250. (The correct answer is 40,320.) In another study by Tversky and Kahneman, participants observed a roulette wheel that was predetermined to stop on either 10 or 65. Participants were then asked to guess the percentage of the United Nations that were African nations. Participants whose wheel stopped on 10 guessed lower values (25% on average) than participants whose wheel stopped at 65 (45% on average).[2] The pattern has held in other experiments for a wide variety of different subjects of estimation.
As a second example, in a study by Dan Ariely, an audience is first asked to write the last two digits of their social security number and consider whether they would pay this number of dollars for items whose value they did not know, such as wine, chocolate and computer equipment. They were then asked to bid for these items, with the result that the audience members with higher two-digit numbers would submit bids that were between 60 percent and 120 percent higher than those with the lower social security numbers, which had become their anchor.[3]
Difficulty of avoiding
Various studies have shown that anchoring is very difficult to avoid. For example, in one study students were given anchors that were obviously wrong. They were asked whether Mahatma Gandhi died before or after age 9, or before or after age 140. Clearly neither of these anchors can be correct, but when the two groups were asked to suggest when they thought he had died, they guessed significantly differently (average age of 50 vs. average age of 67).[4]
Other studies have tried to eliminate anchoring much more directly. In a study exploring the causes and properties of anchoring, participants were exposed to an anchor and asked to guess how many physicians were listed in the local phone book. In addition, they were explicitly informed that anchoring would "contaminate" their responses, and that they should do their best to correct for that. A control group received no anchor and no explanation. Regardless of how they were informed and whether they were informed correctly, all of the experimental groups reported higher estimates than the control group. Thus, despite being expressly aware of the anchoring effect, participants were still unable to avoid it.[5] A later study found that even when offered monetary incentives, people are unable to effectively adjust from an anchor.[6]
Causes
Several theories have been put forth to explain what causes anchoring, and although some explanations are more popular than others, there is no consensus as to which is best.[7] In a study on possible causes of anchoring, two authors described anchoring as easy to demonstrate, but hard to explain.[4] At least one group of researchers has argued that multiple causes are at play, and that what is called "anchoring" is actually several different effects.[8]
Anchoring-and-adjusting
In their original study, Tversky and Kahneman put forth a view later termed anchoring-as-adjustment. According to this theory, once an anchor is set, people adjust away from it to get to their final answer; however, they adjust insufficiently, resulting in their final guess being closer to the anchor than it would be otherwise.[9] Other researchers also found evidence supporting the anchoring-and-adjusting explanation.[10]
However, later researchers criticized this model, because it is only applicable when the initial anchor is outside the range of acceptable answers. To use an earlier example, since Mahatma Gandhi obviously did not die at age 9, then people will adjust from there. If a reasonable number were given, though, there would be no adjustment. Therefore, this theory cannot, according to its critics, explain the anchoring effect.[11]
Another study found that the anchoring effect holds even when the anchor is subliminal. According to Tversky and Kahneman's theory, this is impossible, since anchoring is only the result of conscious adjustment.[12] Because of arguments like these, anchoring-and-adjusting has fallen out of favor.[citation needed]
Selective accessibility
In the same study that criticized anchoring-and-adjusting, the authors proposed an alternate explanation regarding selective accessibility, which is derived from a theory called "confirmatory hypothesis testing". In short, selective accessibility proposes that when given an anchor, a judge (i.e. a person making some judgment) will evaluate the hypothesis that the anchor is a suitable answer. Assuming it is not, the judge moves on to another guess, but not before accessing all the relevant attributes of the anchor itself. Then, when evaluating the new answer, the judge looks for ways in which it is similar to the anchor, resulting in the anchoring effect.[11] Various studies have found empirical support for this hypothesis.[13] This explanation assumes that the judge considers the anchor to be a plausible value so that it is not immediately rejected, which would preclude considering its relevant attributes.[citation needed]
Attitude change
More recently, a third explanation of anchoring has been proposed concerning attitude change. According to this theory, providing an anchor changes someone's attitudes to be more favorable to the particular attributes of that anchor, biasing future answers to have similar characteristics as the anchor. Leading proponents of this theory consider it to be an alternate explanation in line with prior research on anchoring-and-adjusting and selective accessibility.[14][15]
Influencing factors
Mood
A wide range of research has linked sad or depressed moods with more extensive and accurate evaluation of problems.[16] As a result of this, earlier studies hypothesized that people with more depressed moods would tend to use anchoring less than those with happier moods. However, more recent studies have shown the opposite effect: sad people are more likely to use anchoring than people with happy or neutral mood.[17]