Two-Faced Brains

Although human language allowed egalitarian rules whose uniform enforcement would have greatly reduced the advantages to big-brain conniving, humans had the biggest brains of all to unequally evade such rules. (more)

As with most lying or self-deception, homo hypocritus faces a serious implementation problem: how to keep the lies it tells separate from the “real” beliefs on which it acts. Since brains tend to be liberal with interconnections, there is a real risk of cross-talk between contradictory sets of opinions; lies may infect beliefs, and beliefs may infect lies.

I’ve previously discussed one solution: have the different sets of opinions apply to different topics. For example, hold socially-acceptable opinions on far topics, where the personal consequences of actions tend to be smaller, and keep more realistic opinions on near topics, where such consequences tend to be larger. Yes there’s a risk others may notice that you change opinions without good reason as items move from near to far or far to near, but that may be a relatively small price to pay.

A different solution is to have two distinct processing centers, each highly-connected internally, but with only modest between-center connections. One center would manage a coherent set of lies, while the other managed a coherent set of true beliefs. And in fact real brains have exactly this architecture! Left and right brains are highly connected internally, but only modestly connected to each other. Does the left brain manage a coherent set of overt opinions, while the right brain manages a coherent set of covert opinions? Consider:

  1. In all vertebrates left brains tend to control routine behavior (e.g. feeding) while right brains tend to respond to unusual events (e.g. fight/flight).
  2. Left brains tend to initiate actions, via positive feelings, while right brains tend to inhibit actions, via negative feelings.
  3. Compared to other primates, left vs. right human brains differ a lot more in function.
  4. The left human brain manages language’s literal quotably-overt syntax, vocabulary, and semantics, while the right brain handles language’s less-socially-verifiable tone, accent, metaphor, allegory, and ambiguity.
  5. Split brain patients show that left brains are adept at making up respectable explanations for arbitrary right brain behavior.
  6. Right brains tend to be used more in crafting lies, and they can read subtle emotion clues better.
  7. Left brain damage tends to distort behavior in more obvious and understandable ways.
  8. Left brains emphasize decision-making, fact retrieval, numbers, and careful sequenced acts like throwing, while right brains emphasize art, music, spatial manipulation, and recognizing of shapes, patterns, and faces.

It seems that in most animals, left brains tend to manage and initiate actions within the current mode, while right brains watch in the background for patterns and reasons to veto current actions and switch modes. In humans, it seems the current-action-sequencer brain half was recruited to focus more on managing overt rule-following language, decisions, and actions, ready to explain away any apparent rule-violations. The less-introspectively-accessible pattern-recognizing background-watcher brain half, in contrast, was apparently recruited to focus on harder-to-testify-on-and-so-more-easily-covert meaning, opinion, and communication, including art and music.

I’m not saying that overt vs. covert human beliefs map exactly to human left vs. right brains, any more than socially-useful vs. action-practical beliefs map exactly onto far vs. near beliefs. I’m just suggesting that human brain design took pre-existing animal brain structures, such as near vs. far modes and left vs. right brain splits, and recruited them to the task of managing the uniquely human task of hypocrisy: simultaneously espousing and evading rules. In particular, the left-right brain split become an important tool for minimizing undesirable leakage between the overt rule-following images we present to others, and the cover rule-evading actions and communication which better achieve our real ends.

More quotes:

The left hemisphere is specialized not only for the actual production of speech sounds but also for the imposition of syntactic structure on speech and for much of what is called semantics – comprehension of meaning.  The right hemisphere , on the other hand, doesn’t govern spoken words but seems to be concerned with more subtle aspects of language such as nuances of metaphor, allegory and ambiguity. (Ramachandran, quoted in TMHH p56)

No other [vertebrate] species consistently prefers the same hand for certain skilled actions. … The human brain is distinguished from the brains of the great apes by an extraordinary extent of lateralization of function. (more)

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  • Could just be a lack of processing power.

    I’ve seen people break the rules they’re criticising almost within the same breath (usually when it’s about people gossiping and bitching) and they don’t notice the contradiction. But you can point it out to them and it’s not like their brain fails to process the information. They see it – even if they often refuse to acknowledge it. But in the moment as they’re doing it – it just isn’t something they’re focusing on.

    Could be that ironing out contradictions in behaviour and thought takes a lot of processing power that isn’t generally rewarded by the external world so we never evolved systems that internally reward such thought processes.

  • Your “Right brains tend to” link is broken. I believe you meant to link to this. Also, was “differ a lot more” supposed to link to the same page as “sequenced acts like throwing”?

  • Robert Speirs

    For some reason this post reminds me of the old joke about a husband explaining the difference between the topics upon which his word is law and those his wife decides upon. She decides the “little things” in life, such as where they are going to live, how many children they will have and what kind of car they should buy. He decides the important things, like whether China should be allowed to join the United Nations, whether God exists and which candidate should be elected president. Maybe this reflects an opinion about how men and women differently use different sections of the brain in thinking about things.

    • Buck Farmer

      My parents basically operates with a similar division of cognitive labor…my mother handles everything practical, from bills, shopping, schools, home improvement, etc. She also holds sway in matters like who to vote for and which church to attend…however, she unfailingly defers to my father in either important novel situations or when he expresses a strong preference.

      My understanding is that contemporary families in China mostly operate on this model. In the home the mother rules, controls all the finances (father receives an allowance), but in novel or significant decisions the father tends to take precedence.

      If I was so inclined, I might ascribe this to a division between multi-tasking low-risk work and focused high-risk work (i.e. foragers and hunters), but that seems too pat, and I’d like to have a more comprehensive anthropological survey before jumping to evolutionary explanations.

  • Robert Koslover

    Might your ideas here be amenable to testing via experiments with split-brain patients?

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  • acertainshadeofgreen

    An idea that’s related to what you’re talking about is “modularity” which I figure you have probably heard of. If not, check out Robert Kurzban’s work- he recently came out with a book titled “Why Everyone Else is a Hypocrite.”

    Also you would probably like the article “Modularity and the Social Mind: Are Psychologists too Self-ish?” by Kurzban and Aktipis.

  • Point (1), about vertebrates in general, seems particularly dubious. Source?

    The clearest difference between the left and right brains is that the left brain handles the right side of the world, and the right brain handles the left side of the world (the flip-flop is ultimately a consequence of how our eyes work.)

    Many vertebrates don’t have much in the way of a frontal cortex, it’s almost all sensory and motor cortex, so it’s hard to see how the sorts of lateralization of function you talk about could exist in them (and the longitudinal fissure, which separates the “left brain” and “right brain,” is just a cortex thing.)

    Point (3) may be true. I’d be careful about your sources, though.

  • Since men have greater right-left brain separation than women, your theory would suggest that men are more two-faced than women. Is there a consilience here?

  • What’s the evidence that ‘near-mode’ and ‘far-mode’ exist in other animals?

    I’m convinced that those modes are meaningful for humans, possibly as more than just a metaphor for hypocrisy.

  • GudEnuf

    So which side makes up the lies, and which side knows the truth?

  • Buck Farmer

    Brains are generally pretty good at re-organizing around limited damage, if I recall my reading correctly…you can shift a lot of functions from one hemisphere to the other if there is damage.

    Would be interesting to see if these cases (where limited brain damage is compensated by a shift in activity to a non-standard hemisphere) typically results in greater difficulty dealing with social ambiguity, lies, beliefs, etc.

    I’ve heard of these sorts of difficulties emerging in more dramatic cases of brain damage (or in hemisphere separation, whether intentional or not), but I feel that if the compartmentalization hypothesis is true there should be a lot of noise showing up when the brain tries to functions to a new hemisphere.

  • I believe modularity is the default in brains, and that there needn’t be some special mechanism to enforce it. This is because unlike say the knowledge-base AIs we build, we don’t store knowledge as declarative statements and compute behavior based on their implications. Different behavior which seem to use the same piece knowledge could actually be operating with distinct representations of that knowledge, in distinct parts of the brain. Plus, since the knowledge is not stored declaratively but in various parts of the brain in unique forms amenable to various modules in the brain, there cannot be one representation which all modules can then access.

    Consciousness of course seems to have access to knowledge of all types, but then only some information surfaces to consciousness at all. Most of our hypocrisy we are not even consciously aware of.

    People automatically compartmentalize only because it takes actual effort to decompartmentalize. Those on the autistic spectrum who do this do it via propragating in their consciousness their various explicit beliefs. Most ordinary people simply don’t have explicit beliefs in the first place.

  • How do left-handers with their 50% larger corpus collosums fit into this? Women, too, have a larger corpus collosum than do men. Do we see difference among men and women and among left and right handers?

  • “A different solution is to have two distinct processing centers, each highly-connected internally, but with only modest between-center connections. One center would manage a coherent set of lies, while the other managed a coherent set of true beliefs. And in fact real brains have exactly this architecture! Left and right brains are highly connected internally, but only modestly connected to each other.”

    but, but, but … the people on the planet who seem to deceive/self-deceive the most — i.e. neurotypicals — have larger corpus collosums than aspergian types who are not so adept at lying. how does that fit in with what you’re suggesting? seems to me that more connections, at least across the corpus collosum, actually means a greater ability to be economical with the truth.

    • I completely agree. It is much easier to be truthful. You only need to keep track of one version of reality. That makes for much lower computation overhead, allowing allocation to more useful things.

      Since ultimately the only “competition” is with reality, people who can only compete with other humans via lying can only “win” in the short term, that is until there aren’t enough people who can deal with reality left and the technological society that depends on reality collapses.

      With technology it doesn’t take as many people keeping track of reality to support those who cannot, but those who can’t keep track of reality are making it really hard for us who can. We really do need to deal with AGW in a better way than simply denying it.

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