Critical Thinking is Rational

The sub title of In Evidence We Trust is The need for science, rationality and statistics. The subtitle could have been The need for critical thinking. Critical thinking / rational thinking includes scientific thinking, and statistical / probabilistic thinking is a component of scientific thinking. Critical thinking as conceptualized by cognitive scientists has been examined in an array of contexts, and the work of various cognitive scientists led the Stanovich Research Lab to develop the first comprehensive measure of rationality: Comprehensive Assessment of Rationality (CART- 2016).

Rationality consists of two broad categories- instrumental and epistemic rationality. Rational thinking skills are important. They are as important as intelligence. Intelligence and rationality are often dissociated. Research demonstrates that intelligence is often a weak predictor of rationality. This has been shown over a wide range of studies. Intelligence is important, but there is more to good thinking than intelligence. Intelligence reflects reasoning abilities across a wide variety of domains, particularly novel ones. In addition, intelligence reflects general declarative knowledge acquired through acculturated learning. Rationality reflects appropriate goal setting, goal optimization, and holding evidence-based beliefs.

Myths About Critical Thinking

Critical thinking (rational thinking) is good thinking; it involves forming appropriate goals, goal optimization and forming evidence based beliefs. Two common myths associated with critical thinking are emotion prevents critical thinking and critical thinking is synonymous with formal logic. Full article  

Critical Thinking in Modern Society

Educators often pay lip service to the idea of teaching “critical thinking.” But, when asked to define critical thinking, answers are often weak and ambiguous. Common responses to the defining critical thinking include: “teaching them how to think,” “teaching them formal logic,” “teaching them to be thinkers,” “teaching them how to think for themselves,” or “teaching them how to solve problems.” They already know how to think; logic is only a portion of what is needed to increase critical thinking, independent thinking doesn’t necessarily imply critical thinking and teaching them how to solve problems are hard to measure assertions. Full article 

Chapter 2 from In Evidence We Trust features short articles on critical thinking. Some of the articles focus on the rationality intelligence dichotomy. Also included in this chapter are interviews with Keith Stanovich and the Stanovich Research Lab (Keith Stanovich, Richard West and Maggie Toplak). In the interviews with Stanovich, he discusses the development of an RQ Test. In the interview with the Stanovich lab, rationality and intelligence are discussed.

Purchase In Evidence We Trust 2nd Edition (Hale 2019)

Replication Studies: Another Perspective

 Replicable (reproducible) findings are important to science; they are a sub-component of converging evidence. When referring to the replication crisis it is important to understand that what is meant- is lack of replicating statistically significant findings. It would be more precise to say there is a "statistically significant replication crisis." Consider replication from another perspective; the original study failed to detect stat...sign.. (using criteria NHST prevalent with use of frequentist stats), but additional studies detect statistical significance.  What would the implications be??  College instructors should make an effort to address this condition- non-significant precedes significant findings. Students are often advised no need to try to replicate non-significant findings, but sign..findings should be replicated. This implies that the non-sign....findings must be accurate (if they occurred first), even though all studies are susceptible to flaws.   

Gelman asserts the time-reversal heuristic needs consideration: "One helpful (I think) way to think about this episode is to turn things around. Suppose the Ranehill et al. experiment, with its null finding, had come first. A large study finding no effect. And then Cuddy et al. had run a replication under slightly different conditions with a much smaller sample size and found statistically significance under non-preregistered conditions. Would we be inclined to believe it?"    

What are some different types of replication studies?

There are least 3 general types of replication studies- direct replication, conceptual replication and replication-plus-extension. In direct replication, researchers attempt to conduct research using methods that are as close as they can to those used by original researchers. The more transparent the original research the easier it will generally be to directly replicate....

Replication is an important part of science. Non-sign..and sign...studies may be flawed. An array of variables determine the value of the findings- publication source, funding sources, study replication, study design, sample size, conflicting interest, sampling error, different measures of reliability and validity, reporting limitations, and other possible criticisms of the study. 

The top-tier of scientific evidence is converging evidence.   

So Many Brain Myths

Discussions on the brain are ubiquitous. Magazines, books and T.V. are saturated with  information related to the brain. Lots, if not most of it is wrong.

How Many Neurons Are in the Human Brain?

When I was an undergraduate in graduate school, I learned the human brain consists of 100 billion neurons (Kolb and Whishaw 2009). This number was reported in scholarly journals, textbooks, and in college lectures. It was accepted as fact. I never saw a citation of an original source to support the claim, nor did I ever hear anyone question whether or not there was evidence to support it. I just assumed it was common knowledge and must be supported by a large body of data. Even the general public knew that the human brain consists of 100 billion neurons. In addition to academia’s dissemination of the supposed fact, popular media embraced and promoted the 100 billion neuron idea...

  

The Allure of Brain Science

The media have become fascinated with brain images—and the use of those images to explain almost everything. Neuroscience (the scientific study of the nervous system, in many cases focusing only on the brain) has made a mark in mainstream media and everyday conversation. You have probably seen headlines such as “This Is Your Brain on Sugar,” “The Brain’s Evil Spot,” or “Brain Based Learning.” These phrases, and the stories associated with them, generally hold some truth but at the same time are misrepresented and often fuel false beliefs and misconceptions. As an example, consider the implications of the so-called “Sugar Brain.” Proponents claim that consumption of sugar can activate the same brain reward mechanisms (dopamine pathway referred to as mesolimbic dopamine system) as those activated when consuming addictive drugs. Some of the same brain areas are activated (varying in strength and intensity) when consuming sugar and drugs, but other stimuli also activate the mesolimbic dopamine system. The mesolimbic dopamine system is rich in dopaminergic neurons. Dopamine cell bodies (parts of brain cells where dopamine is synthesized) are located in the brainstem...

 

The Truth About Nootropic Supplements

Nootropic substances—from the Greek words meaning “mind-bending” –are ingestible chemicals often promoted for their cognitive enhancing properties (Jasanoff 2018). According to companies selling nootropic products, benefits of using the products include prevention of cognitive decline, enhanced memory, increased learning, improved concentration, and rapid cognition. Nootropic drugs include stimulants like amphetamine and methylphenidate, marketed under the names Adderall and Ritalin, as well as sleep suppressants like Modafinil. Nootropics also include a range of dietary supplements...

 

 

 

  

Replication Studies in Science

Ideally, scientific research should be replicable (reproducible). The research should use processes that can be used by others wanting to conduct a similar or the same study. When referring to the replication crisis it is often understood that what is meant is lack of replicating statistically significant findings. It would be more precise to say there is a "statistically significant replication crisis." It is possible that original studies that fail to show significance may demonstrate a type 2 error- missing an effect. This could occur do to a number of methodological or statistical issues. As an example, when I conducted a study on expectations influence on food liking the finding was insignificant; when I ran a statistical power analysis it revealed I needed a larger sample, considering effect size and p-value to find significance. Statistically significant and insignificant finding should be replicated, and they should involve different type of replications using samples with varying characteristics.

What are some different types of replication studies?

There are least 3 general types of replication studies- direct replication, conceptual replication and replication-plus-extension. In direct replication, researchers attempt to conduct research using methods that are as close as they can to those used by original researchers. The more transparent the original research the easier it will generally be to directly replicate. In conceptual replication researchers address same topics, questions, but use different methods. Variables are manipulated and measured using different strategies, but conceptualization remains intact. In a replication-plus-extension study, researchers replicate original studies, but also add variables, that may include different operationalizations.

What are the implications of replication studies?

Extra weight is often given to studies that are replicated (also find significance) outside of the original lab, or when conducted by researchers other than the ones making the original findings. A red flag is indicated if only a specific group or lab is able to make a finding. Why is it others can't make the finding? It is essential that researchers are transparent with their methods and all relevant research materials. Strong evidence is the result of various studies; not a single study, or series of studies that can only be found by one research group. To reiterate, scientific progress is cumulative; it develops as a product of the work, of sometimes many people. In some cases it is necessary to repeat studies that didn't find significance. The original study might be flawed. The Apex of evidence is converging evidence. Various research methods, stats, models and inferential strategies have limitations- it is the preponderance of evidence from various lines of inquiry that converge to produce the highest level of evidence.

For further discussion on issues with scientific methods refer to -   In Evidence We Trust 2nd Edition  

Various articles on replication from Andrew Gelman's site