Critical Thinking: The Biological Basis of How We Do It, Learn It, and Teach It

Critical Thinking:The Biological Basis of How We Do

It, Learn It, and Teach It

Peter L. Walton, M.D.Associate Dean for Academic Affairs

School of Public Health and Information Sciences

iClicker Question 0 (15 sec.)“Critical thinking is a cognitive activity that:• can be learned,• is difficult to teach or evaluate,• requires an organized and rational

approach,• and to succeed must become a nearly

automatic function.”A. TrueB. False

Agen

daDeclarationsCentral Question and F&PCsWarm-up

– Others’ thoughts on critical thinking– Exercises for you to feel less certain about:

• Your senses• Your cognition• Your objectivity

Groundwork– Natural selection– Genetics, et al.– Neuroscience

Individual vs. team sportTeachers vs. studentsConclusionsSuggestions

WARNING: All of this is 46% of the slides, doesn’t mention critical thinking at all, but is indispensible for making any sense of the rest.

• My goal is awareness, not understanding or agreement.• I’ll be covering lots of dots

quickly, often without connecting them.• These are left for you to do at

your leisure.

… and we’re off …

DeclarationsI’m an unabashed and unrepentant i2a groupie (redundantly speaking).I’m all for critical thinking but accept that it too is subject to critical thinking.Everything in my presentation is based on currently accepted evidence.– However, a lot of what I’ll say, while based on evidence, is still conjectural and in italics.

I currently accept the following as fundamental for critical thinking:– Critical thinking is an instance of the scientific method, which includes emotion.– Whether free will exists or not is a distracter. Ditto for consciousness.– Biases/heuristics are both good and bad for critical thinking.– Certainty is a emotion.– Most approaches to critical thinking (e.g., Paul-Elder) are based on a classification

system.– All classification systems are falsifiable (see Gödel) but many are extremely useful. – My biases lead me to accept and communicate these fundamentals.– Some or all of these fundamentals are likely in error.

iClicker Question 1 (15 sec.)With which of the following of my declarations are you the MOST UNCOMFORTABLE?

A. Critical thinking is an instance of the scientific method, which includes emotion.

B. Certainty is a emotion.

C. Most approaches to critical thinking (e.g., Paul-Elder) are based on a classification system.

D. All classification systems are falsifiable (see Gödel) but many are extremely useful.

E. Other.

No response = None

Central Question

"Can we really think critically let alone teach it?"

Fundamental & Powerful Concepts

• Natural selection• Sexual reproduction• Intuition/emotion• Bias/heuristic• Socialization

Any questions?

Quick Peek at the End of the Book

Can we really think critically?

Yes. But not the way we think we do.

Let alone teach it?

Yes. But not the way we think we are.

Agen

daDeclarationsCentral Question and F&PCsWarm-up

– Others’ thoughts on critical thinking– Exercises for you to feel less certain about:

• Your senses• Your cognition• Your objectivity

Groundwork– Natural selection– Genetics, et al.– Neuroscience

Individual vs. team sportTeachers vs. studentsConclusionsSuggestions

Fun part

Others’ Thoughts on Critical Thinking“The human understanding supposes a greater degree of order…in things than it really finds.” -- Francis Bacon, Novum Organum, 1620

“Truth will sooner come out of error than from confusion.” -- Francis Bacon, ?1623

“Our whole problem is to make mistakes as fast possible.”-- John Wheeler, presumably updating Francis Bacon

“The real purpose of [critical thinking] is to make sure Nature hasn’t misled you into thinking you know something that you actually don’t.”-- Robert Pirsig, Zen and Art of Motorcycle Maintenance, 1974

“The first principle is that you must not fool yourself -- and you are the easiest person to fool.” -- Richard Feynman, 1974

“The greatest obstacle to discovery is not ignorance -- it is the illusion of knowledge.” -- Daniel Boorstin, Librarian of Congress, 1984

iClicker Question 2 (10 sec.)

A. 60%B. 70%C. 80%D. 90%E. 100%

The BLUE line CD on the right is what percent as long as the RED line AB on the left?

The BLUE line CD on the right is what percent as long as the RED line AB on the left?

E. 100%

iClicker Question 4 (15 sec.)• I toss two coins, promising that if at least one

of them comes up heads, I will tell you. • I look at both coins and volunteer that at least

one is indeed a head.

What’s the chance that the other is also a head?

A. 25% C. 50% E. 75%B. 33% D. 66%

Two Coins But No Fountain• I toss two coins, promising that if at least one of

them comes up heads, I will tell you.• I look at both coins and volunteer that at least

one is indeed a head.

There are four possible cases: HH, HT, TH, TT.Three of these have at least one head: HH, HT, THOf those three, one has a second head: HH

The chance of the other being a head is 33% (answer B).

iClicker Question 6 (30 sec.)Which of these cards must you turn over to determine whether this rule is true or not:

“If there is a vowel on one side, there is an even number on the other side”?

A K 2 7

A. A only C. A and 2 E. otherB. 2 only D. A and 7

A Card GameRule” “If there is a vowel on one side, there is an even number on the other side.”You must turn over the “A” card to see if there’s an even number on the other side (verification)and the “7” card to see if there’s a vowel on the other side (falsification).The other cards are of no use.

Everybody turns over “A”; 4% turn over “7”, while the rest either are done or turn over the “2” (confirmation bias).

A K 2 7

Answer: D. A and 7

Agen

daDeclarationsCentral Question and F&PCsWarm-up

– Others’ thoughts on critical thinking– Exercises for you to feel less certain about:

• Your senses• Your cognition• Your objectivity

Groundwork– Natural selection– Genetics, et al.– Neuroscience

Individual vs. team sportTeachers vs. studentsConclusionsSuggestions

Challenging part

Natural SelectionA very brief synopsis of natural selection:

– Natural selection is not blind – it simply has no intent or purpose.

– The outcome of natural selection is selective persistence – nothing else.

– Persistence requires replication, which requires replicators to have fidelity, fecundity, and longevity – nothing else.

– Lineages that tend to persist tend to persist.

– Characteristics that enhance lineage persistence tend to persist with their lineages.

And intuition is one of these characteristics.

IntuitionCognitive scientists have found that most (>99%) of our day-to-day “decisions” make essentially sole use of our ability to “think” without awareness.

This is intuition.

Our use of intuition does not decrease much when what we are deciding is important (e.g., life and death) or unimportant (e.g., what to wear).

In fact, the use of intuition increases as expertise in an area increases.

And biases are essential agents in intuition.

BiasesA vital persistence characteristic in natural selection is the ability to act quickly.Simple heuristics evolved to support acting quickly.These heuristics are biases.Some are deemed “good” by humans, e.g.:

– Type 1 vs. type 2 errors– Certainty

Some are deemed “bad” by humans, e.g.:– Framing– Confirmation

And all of them evolved by enhancing persistence.

A Really Major CharacteristicSexual reproduction:–Enhances persistence in presence of parasites–Enhances diversity within lineages

Consequences:– Socialization:

• Group identity (e.g., tribalism, both by blood and mating and, in humans, by acquired characteristics, e.g., golf playing)

• Specialization • Specialty selection by distinctions of traits and/or lineages• Differential and non-linear valuations of specialties

– Sexual selection:• Handicap principle

And everything is governed by genetics (sort of).

Genetics, et al.DNA–Everything life is capable of is dictated by DNA – but

with important additional considerations.

Genes – about 2-3% of DNA–Encoded for structural and worker molecules –

protein.

RNA – uncertain % but probably all the rest–Encoded for controlling production of proteins and

RNA and for controlling the control of RNAThere is no “junk” in DNA.

More Genetics, et al.Epigenes– RNA that controls DNA and its expression and controls RNA

in response to the environment

Nature vs. nurture– There is no “vs.” – they cooperate, more or less–DNA (nature) enables the environment (nurture) to modify

the expression of DNA (nature) to adapt to the environment (nurture). Repeat until dead.

And neuroscience is learning how genetics, et al. provide mechanisms for persistence of intuition, cognition, and decision making.

iClicker Question 8 (15 sec.)Between birth and sexual maturity, which of the following happens to our brain’s neurons, on average?

A. We double the number of neurons.

B. We increase the number of neurons by 23%.

C. We keep the same number of neurons.

D. We decrease the number of neurons by 12%.

E. We halve the number of neurons.

NeuroscienceNeuron pruning–Between birth and sexual maturity, we “prune” (i.e., kill)

50% of the neurons we’re born with.–This is in response to our environment (adaptation).–Post-pruning we add and prune neurons throughout our

lives to a much lesser extent.

Synapse pruning– We add and prune connections among neurons in adapting

to our environment, primarily during initial neuron pruning.– Post-pruning we add and prune synapses throughout our

lives, again to a much lesser extent.

NeuroscienceGlial cells– Outnumber neurons by ~9:1.– Initially thought to only provide structural

support for neurons.– Recently found to also “nurture” neurons

– blood supply, nutrients, and connection speed.• Each neuron has many caretaker glial cells.

• Each glial cell may be caretaker to several neurons.

– Likely responsible for both neuron and synapse pruning.

More NeuroscienceMirror neurons–Appear to be involved in understanding the actions of

others (by simulation and empathy) and learning new skills (by imitation).– Located in many parts of the brain.

Prefrontal cortex–Primary location for integration of emotion, intuition, and

cognition.– Essential for decision making.–Matures at differing stages and rates by gender and

individual.

Token Picture and Quote

Prefrontal cortex

“Depending on their target of influence, representations in the PFC can function variously as attentional templates, rules, or goals by providing top-down bias signals to other parts of the brain that guide the flow of activity along the pathways needed to perform a task.” Miller EK, Cohen JD (2001). "An integrative theory of prefrontal cortex function". Annu Rev Neurosci 24: 167–202.

Even More NeuroscienceExperiment: Motor action by intention– Finding: Sequence is not decide-prepare-act but rather

prepare-decide-act.– Finding: Deciding follows preparing by about 0.4 second.

Experiment: Timing of action and awareness of action– Finding: Awareness follows action by about 0.4 second.

Experiment: Neuron behavior in binary-bet game.– Finding: Neuron activity indicated bet decision on

average 2.8 seconds before subjects “decided” on bet.

Still More NeuroscienceExperiment: Differentially rewarded and penalized multi-card deck game (Iowa Gambling Task):– Finding: Most subjects identify “good” and “bad” decks

after 40-50 card flips.– Finding: Subjects show stress responses to “bad” decks

after about 10 card flips.– Finding: Younger college subjects perform worse than

older ones (?immature prefrontal cortex).– Finding: College education is predictor of poorer

performance (?emphasis on rational thought vs. emotion).

One More from NeuroscienceSubjects: Individuals whose prefrontal cortex has been

damaged such that integration of emotion is decreased or absent.

Finding: Unable to make everyday decisions (e.g., Coke or Pepsi) and life-altering decisions (e.g., change jobs).

Conclusion: Emotion is essential for decision-making.Theory: Immediate gratification trumps long-term

gratification even knowing the potential negative results of the former in the long run.

Agen

daDeclarationsCentral Question and F&PCsWarm-up

– Others’ thoughts on critical thinking– Exercises for you to feel less certain about:

• Your senses• Your cognition• Your objectivity

Groundwork– Natural selection– Genetics, et al.– Neuroscience

Individual vs. team sportTeachers vs. studentsConclusionsSuggestions

Frustrating part

iClicker Question 9 (10 sec.)

Critical thinking is:A. An individual sport.B. A team sport.C. Both.D. An illusion.E. I have no idea.

Socialization

Individual vs. Team Sport, Round 1

A brief recap:

Conclusion:–Our brains evolved for

socialization

– and for selection– and selection is a dynamic mix

of competition, cooperation, and collaboration.

Lineage persistence

Sexual reproduction

Sexual selection

Specialization

Specialty selection

Brain functions

Genetics, et al.

Natural selection

Individual vs. Team Sport, Round 2

A single person doing science in isolation could be doing science or could be fooling herself and doing anecdotes.– Note: The plural of anecdote is not data.

A good way for her not fool herself is to for others do the same things and see if they get the same results. A.k.a. the scientific method.The same must hold for critical thinking since it’s an instance of the scientific method.So critical thinking is a team sport!

Individual vs. Team Sport, Round 3

Hold on there, You. I think critically – I put together this presentation after all!True. Specialty selection does not result in everyone in the specialty having the same level of performance in the specialty.Many scientists frequently have their findings confirmed.So critical thinking is an individual sport to an extent that varies among critical thinkers.And the way a critical thinker determines his own extent is by sharing his thinking with other critical thinkers to see what they think about it. He also learns about others’ thinking (?partly via mirror neurons).

Individual vs. Team Sport, Round 4

So critical thinking is an individual sport up to a point

that varies by individual and within an individual by ability and practice,that requires critical thinking to be a team sport for practicing,and that ultimately is a team sport determining the extent to which an individual can play individually and still be part of the team.

Teachers vs. StudentsItem Teacher (modal) Student (modal)

Intuition well-trained, stable in training, unstable

Inventory of biases large, organized, integrated, slowly changing

small, unorganized, poorly connected, rapidly growing

Sexual selection established in development

Inventory of handicaps established in development

Replication yes no

Socialization established in development

Specialty selection established, stable in development, unstable

Prefrontal cortex mature immature, esp. in males

Critical thinking credential Ph.D. high school diploma

Critical thinking team member of established team(s) Unaware of concept or need

Critical thinking practice 10 years or more 3-4 years at most, mostly social

Critical thinking arena academe, academic discipline high school, socialization

Score: Teachers 12, Students 0But there’s more …

… and the bottom line …

Item Teacher (modal) Student (modal)

Percent who will be teachers 100% <10% (increases at graduate level)

Individual critical thinking advanced level, aware of level beginning level, unaware of levels

Expectations of other role self-initiated intellectual interest and activity

self-initiated acceptance, guidance, mentoring

Experience in other role hindsight bias, self-serving bias none

Mirror neuron contribution “students aren’t that interested in my course” “teachers are just like my parents”

Emotional contribution “i’m not as good a teacher as i think I am”

“i’m not as good a student as i used to be”

Cognitive contribution “students aren’t as prepared as i want them to be and i am” “teachers aren’t that interested in me”

Mirror neuron contribution “students aren’t that interested in MY course” “teachers are just like MY parents”

Emotional contribution “I’M not as good a teacher as I think I am”

“I’M not as good a student as I used to be”

Cognitive contribution “students aren’t as prepared as I want them to be and I am” “teachers aren’t that interested in ME”

Prefrontal cortex decision business as usual business as usual

Conclusions

Can we really think critically?– Yes, but learning how took lots of time and practice in

an environment that nurtured implicit teamwork.–And it still requires continual practice.

Let alone teach it?– Yes, but we need to build in lots of time and practice

in an environment that provides explicit teamwork.–And we need to balance what we love (content) with

what we use (critical thinking).

iClicker Question 10 (10 sec.)

Critical thinking is:A. An individual sport.B. A team sport.C. Both.D. An illusion.E. I have no idea.

SuggestionsHere are some suggestions based on what we know about natural selection, genetics, and neuroscience:–Discuss the above and the teacher vs. student dilemma.–Hold impromptu class discussions about course issues.– Balance content and technique .• Depth with critical thinking vs. breadth with factual recall.

– Evaluate deliverables using intellectual standards.• Start with a few then add more as students catch on.

–Use a repeated exercise that has different content but the same format, intent, and evaluation standards.• Practice, practice, practice!

Suggestions (cont.)– Include an analytic report using the elements of thought

(adapted) that is revised until it meets defined evaluation expectations.• Make achievement the constant and time the variable.

–Do group activities.• T-P-S, peer evaluations, presentations

– Schedule office hours with groups of five students.• Discuss course, philosophy, life, current events, whatever.

– Show and discuss a relevant movie or documentary.– Implement team learning.• But only if you’re committed to making it work.

Final ThoughtsActive learning simply means keeping students cognitively active.–This requires them to be under a mild but

perceptible level of stress.–Expect it and nurture it.–Tell students about it early on (e.g., class 1).

Essential aspects of learning and rationality are intuition and emotion.– Don’t avoid them. Enjoy using them.–Tell students about them early on (e.g., class 1).

iClicker Question 12 (15 sec.)“Critical thinking is a cognitive activity that:• can be learned,• is difficult to teach or evaluate,• requires an organized and rational

approach,• and to succeed must become a nearly

automatic function.”A. TrueB. False

Questions? Answers?

So long . . .and thanks for all the fish.