Published by
Stanford Medicine

Evolution, Genetics, Research, Stanford News

Dumb, dumber and dumbest? Stanford biologist suggests humans on a downward slide

Dumb, dumber and dumbest? Stanford biologist suggests humans on a downward slide

I laughed out loud when I saw the many news reports today about the latest articles by Stanford developmental biologist Gerald Crabtree, MD. Not because the reports were wrong or because the research is poor. It’s just that the topic is guaranteed to make nearly anyone either laugh or cry — particularly someone (ahem, ME) who has recently been feeling less and less smart with each birthday.

Crabtree hypothesized in two articles published today in Trends in Genetics that humans are slowly accumulating genetic mutations that will have a deleterious effect on both our intellect and emotional stability. The reason, he believes, is the relative lack of selective pressure during the past 3,000 years. He begins boldly:

I would wager that if an average citizen from Athens of 1000 BC were to appear suddenly among us, he or she would be among the brightest and most intellectually alive of our colleagues and companions, with a good memory, a broad range of ideas, and a clear-sighted view of important issues. Furthermore, I would guess that he or she would be among the most emotionally stable of our friends and colleagues.

It’s an intriguing point. I’ve recently been re-educating myself about ancient Greek history,and I’ve been newly amazed about the breadth and depth of the philosophy and ideas propounded by people thousands of years ago.

Crabtree calculates that between 2,000 to 5,000 genes are likely required to maintain optimal intellectual acuity and emotional well-being. Extending his theory, it’s likely that we’ve each accumulated at least two harmful mutations during the intervening millennia. (Case in point? I just had to look up how to spell that last word.) Why? Well, according to Crabtree:

It is also likely that the need for intelligence was reduced as we began to live in supportive societies that made up for lapses of judgment or failures of  comprehension. Community life would, I believe, tend to reduce the selective pressure placed on every individual, every day of their life. Indeed that is why I prefer to live in such a society.

Don’t we all? But although it’s disheartening to think that we’re locked in a downward spiral, it’s way too soon to panic. Crabtree emphasizes that our demise will be slow:

However, if such a study found accelerating rates of accumulation of deleterious alleles over the past several thousand years then we would have to think about these issues more seriously. But we would not have to think too fast. One does not need to imagine a day when we could no longer comprehend the problem, or counteract the slow decay in the genes underlying our intellectual fitness, or have visions of the world population docilely watching reruns on televisions they can no longer build. It is exceedingly unlikely that a few hundred years will make any difference for the rate of change that might be occurring.

Whew.

Photo by CollegeDegrees360

3 Responses to “ Dumb, dumber and dumbest? Stanford biologist suggests humans on a downward slide ”

  1. Neal Orr Says:

    In the meantime we drink liquids and eat foods containing HFC and the tiny cumulative bit of mercury in all of it.

    That explains what I’ve seen in the past 40+ years. Remember when Pepsi and Coke switched? That was 1968. Look at the difference between those born near then or later and those before, mercury affects young developing brains by far worse than the over-10’s. Or even just look into how much more HFC goes into so much we eat and drink any more.

    It won’t take any 1000+ more years before we’re at Idiocracy anyway, maybe less than 100.

  2. Keith Sutyak Says:

    If one thinks of the mind as a muscle which improves with exercise (no not the proverbial “muscle-head”), then it is easy to see why people are less bright. They don’t get enough exercise, primarily because of mindless activities such as video games, movies, computer aides, and watching television. Other reasons are clear: 1. Pygmalion effect – The thought that encouragement leads to better performance; while this is partially true, our society perverts this by codling those with less intellect to shield their egos, and thus defeat a more powerful influence – rejection of failure; 2. Moral bankruptcy. Our morals have degraded so badly, that we no longer have the integrity to admit poor performance (from which we should learn), nor do we have sufficient introspection to improve upon ourselves; 3. Nepotism. The preservation of family and friends, which many times rewards incompetence vice performance; 4. The Gene pool issue – we develop an ultra safe society where stupidity is allowed to survive and propagate (Let’s call it “reverse Darwinism”). The people who instituted these idiocies are called the Left – which fittingly represents the part of the intelligence bell curve that they represent.

  3. Lisa Rhein Says:

    Interesting concerns, conclusions, and opinions. Certainly supportive societies make it easier to forget that a mistake, inattentiveness, or plain stupidity can cost us “life or limb”. They reduce the need to be on certain kinds of alert, all the time.
    The statement that particularly caught my eye is the argument that associates a lack of (mental/physical) “exercise” with (3 out of 4 items) how we spend our leisure time. What seems to escape attention in most such discussions is that many, if not most of us spend our time at work (school/work) and that the tasks our work requires of us are for many of us truly and actually mind-deadening and stultifying. Taking the human animal as an organism and strapping it into a chair and desk inside an enclosure for upwards of 8 hours a day, curtailing the interaction with the changing, complex, surprise-filled outside environment, forcing constant repetition on it … those are factors that need to be addressed more often.

Comment


Please read our comments policy before posting

Stanford Medicine Resources: