Cognitive Thrift 3 – Size

In-Sight Publishing

Cognitive Thrift 3 – Size

Scott Douglas Jacobsen & Rick Rosner

May 8, 2017

[Beginning of recorded material]

Scott Douglas Jacobsen: What are some of your ideas about cognitive thrift with respect to size?

Rick Rosner: One, it requires a lot of resources to run a thinking organism. It costs a lot in terms of energy. Two, independent thought as opposed to following long-established rules can be risky. Thought involves error.  Three, thought can add instability. Both to the species by being disruptive and to the individual by making it more likely to go crazy. I guess that an organism with a complex brain is more likely to suffer disorders of thought than an organism with a less complex brain.

Four, big brains are dangerous during childbirth. Five, they require more time to pass on cultural knowledge. And they require that babies be born less mature than animals with smaller brains. When you look at the human childbirth model, the head is as big as it can be. It is just big enough to get out of the pelvis, but it is not big enough for an adult brain. So, you’ve got this 10 or 12 years of learning and continuous brain growth, and requires humans to have longer lifespans. It is a whole different model of survival. Say possums, which are dumber, and have an average lifespan of two years.

Jacobsen: What would be some of the consequences in terms of cognitive biases with an expanded cortex – which comes with expanded cognitive capacities and can be put things on the ‘radar’ of the organism’s conceptual landscape but leaves an area for cracks?

Rosner: It’s like when you’re buying the car. Is it worth the spray coat to protect from salts? Is it worth the Sirius XM radio? The thought expanding capacities can be at the expense of other capacities. They can help the thinking organism find ore exploitable regularities to improve their situation or to avoid risk. You might be able to argue that our brains are at the optimum size for risk that we face. In fact, you can make an overall argument that brains which are expensive are only the size that they need to be for the organism to survive long enough to raise that next generation of organism, and depending on the environment and other factors.

So, it’s jocks vs. nerds throughout evolution and amongst species, where species that are well-adapted to stable environments may not need to think as much as much as species in changing environment. Once they are set in an environment, like some kinds of molluscs or clams, their brains are there when they’re looking for a place to spend the rest of their lives, but when it’s done their brain goes away. I don’t know. I’ll have to Google it.

[End of recorded material]



Rick Rosner

American Television Writer


Rick Rosner


Scott Douglas Jacobsen

Editor-in-Chief, In-Sight Publishing


In-Sight Publishing


[1] Four format points for the session article:

  1. Bold text following “Scott Douglas Jacobsen:” or “Jacobsen:” is Scott Douglas Jacobsen & non-bold text following “Rick Rosner:” or “Rosner:” is Rick Rosner.
  2. Session article conducted, transcribed, edited, formatted, and published by Scott.
  3. Footnotes & in-text citations in the interview & references after the interview.
  4. This session article has been edited for clarity and readability.

For further information on the formatting guidelines incorporated into this document, please see the following documents:

  1. American Psychological Association. (2010). Citation Guide: APA. Retrieved from
  2. Humble, A. (n.d.). Guide to Transcribing. Retrieved from

License and Copyright

In-Sight Publishing and In-Sight: Independent Interview-Based Journal by Scott Douglas Jacobsen is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
Based on a work at and


© Scott Douglas Jacobsen, Rick Rosner, and In-Sight Publishing and In-Sight: Independent Interview-Based Journal 2012-2017. Unauthorized use and/or duplication of this material without express and written permission from this site’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Scott Douglas Jacobsen, Rick Rosner, and In-Sight Publishing and In-Sight: Independent Interview-Based Journal with appropriate and specific direction to the original content.

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