Thinking & Decision Making I Notes PDF

# Thinking and Decision Making I ## Reading: Passer et al. Psychology, The Science of Mind and Behaviour, pp. 343-358 (Chapter by me on blackboard) ## After this lecture you should be able to: - Describe two common biases observed in human reasoning - Define heuristics, and explain their advant...

# Thinking and Decision Making I ## Reading: Passer et al. Psychology, The Science of Mind and Behaviour, pp. 343-358 (Chapter by me on blackboard) ## After this lecture you should be able to: - Describe two common biases observed in human reasoning - Define heuristics, and explain their advantages and limitations # Humans are smart. Why do we sometimes get it so wrong? Salience bias: assessing something as more prevalent if it comes to mind very readily. The image is of a shark with its mouth open. A pair of legs is visible in the water above the shark's mouth. # Another common error: Confirmation bias Darley and Gross (1983): Showed participants a video of an oral test. - Two participant groups - This is not just stereotyping - Raters attended more to evidence confirming their expectations # Confirmation Bias in Psychology - Research: Testing a favourite theory - Clinic: Understanding the cause of distress ## There's a short video animation below this lecture clip that gives some other examples of confirmation bias You might like to stop the lecture recording here and take a look. Don't forget to come back! # See you in the next clip Before you start the next clip, make sure you watch the short video animation on confirmation bias. You'll find it right below this lecture. See you in the next lecture clip! # Why do we make these errors? Tversky and Kahneman (1972): - We base most judgment/decisions on heuristics - Heuristics = quick rules of thumb that work well in most situations ## Two examples: - The representativeness heuristic - The availability heuristic # The Representativeness Heuristic Tversky & Kahneman (1982): Linda is 31 years old, single, outspoken and very bright. She majored in philosophy. As a student, she was deeply concerned with issues of discrimination and social justice, and she also participated in anti-nuclear demonstrations. | **Likelihood** | **That:** | | --------------- | ---------------- | | Highest | Linda is a feminist | | Lowest | L is a bank teller | The table is not visible on the truncated image. It shows a scale from 1 to 8, with 'Highest' at the top and 'Lowest' at the bottom. Participants were asked to rate the likelihood of the two statements; that Linda was a feminist and that she was a bank teller. # The Representativeness Heuristic The representativeness heuristic: To classify something, we assess how closely it matches our 'prototype' for that group. The image is a silhouette of a dog. # A Real Life Example Missed signs mean more women die of heart attack Women suffering a heart attack are less likely to have been correctly diagnosed than men (Asaria et al., 2017). **Prototypical heart disease patient:** an overweight, middle-aged male. # The Availability Heuristic = the tendency to assess outcomes as more probable if they come to mind readily This is the core principle underlying the salience bias The image is of a shark with its mouth open, with a pair of legs visible in the water above the shark's mouth. # But most of the time heuristics work! AND, they serve an important function. Let's learn why... # Consider this Scenario An experienced driver is chatting to a passenger. A pedestrian appears near the side of the road. Without missing a beat in the conversation, the driver tightens her grip on the steering wheel, and gently squeezes the brakes to slow the car; then after a short moment, she releases the brakes and returns to her previous speed. The image is of a woman driving a car, chatting with a passenger. # Logical thought costs time and mental resources https://www.youtube.com/watch?v=Kho5KvPBDSw # Dan Kahneman Thinking Fast and Slow ## System 1 (Fast) - automatic - Draws on concepts, routines and rules of thumb acquired through extensive practice. ## System 2 (Slow) - Slow, effortful - Needed in unfamiliar situations - Or where creativity is called for - Or where precision is paramount The image is of the book 'Thinking, Fast and Slow' by Daniel Kahneman. # "Fast" Thinking and Expertise Experience builds richer knowledge structures and rules of thumb: - patterns of movement that signal the need to brake - the appearance; soft vs. hard snow - Chess board patterns and sequences of moves The image is of three small photographs: snow skiers going down a slope, a woman on a ski ride, and a pair of men playing chess. # Some Terms - Heuristics = rules of thumb about the world - Schemas = mental knowledge structures based on experience (e.g., snow textures) - Scripts = common action routines (e.g., going to a restaurant) # Is there a Cost to Expertise? Heuristics are rapid, they may confer overconfidence. Berner & Graber (2008): - Doctors were given case descriptions. - Some led to high disagreement between doctors - However, each individual doctor was confident they were correct The image is of a doctor asking a patient who is smiling and sitting on a couch a question. # In Conclusion - Fast/automatic routines guide an enormous amount of our behaviour and judgements. - They are essential for our day-to-day functioning. - But we need to be aware of their downsides...