17 Mar

“Scientists now belive mental abilitites decline from age 27” (sic) says the Daily Telegraph this morning; clearly someone over the age of 27 must have composed that headline! And to think how rabid the Murdoch press is sometimes on the matter of declining standards in literacy!

The new research, reports The Mail on Sunday newspaper in the UK,  shows that our mental abilities begin to decline from the age of 27 after reaching a peak at 22.

The researchers studied 2,000 men and women aged 18 to 60 over seven years. The people involved, mostly in good health and well-educated, had to solve visual puzzles, recall words and story details and spot patterns in letters and symbols.

Similar tests are often used to diagnose mental disabilities and diseases, such as Alzheimer’s  and other forms of dementia.

The research at the University of Virginia, reported in the academic journal Neurobiology Of Aging, found that in nine out of 12 tests the average age at which the top performance was achieved was 22.

The first age at which performance was significantly lower than the peak scores was 27 – for three tests of reasoning, speed of thought and spatial visualisation. Memory was shown to decline from the average age of 37. In the other tests, poorer results were shown by the age of 42.

Professor Timothy Salthouse said the results suggested that therapies designed to prevent or reverse age-related conditions may need to start earlier, long before people become pensioners.

Good news for Thomas, among others, I suppose.

You have to subscribe to Neurobiology of Aging to read the original, but there is an abstract.

Cross-sectional comparisons have consistently revealed that increased age is associated with lower levels of cognitive performance, even in the range from 18 to 60 years of age. However, the validity of cross-sectional comparisons of cognitive functioning in young and middle-aged adults has been questioned because of the discrepant age trends found in longitudinal and cross-sectional analyses. The results of the current project suggest that a major factor contributing to the discrepancy is the masking of age-related declines in longitudinal comparisons by large positive effects associated with prior test experience. Results from three methods of estimating retest effects in this project, together with results from studies comparing non-human animals raised in constant environments and from studies examining neurobiological variables not susceptible to retest effects, converge on a conclusion that some aspects of age-related cognitive decline begin in healthy educated adults when they are in their 20s and 30s.

Now I do have a large hat size, so I am encouraged by another bit of research I found here.

Confirming earlier studies, a British study of 215 men and women aged between 66 and 75, has found that the larger a person’s head, the less likely their cognitive abilities are to decline in later years. Those with the smallest heads had a fivefold increased risk of suffering cognitive decline compared with those with the largest heads. Encouragingly, however, this doesn’t mean you’re doomed at birth — the researchers found that it wasn’t head circumference at birth that was important, but head size in adulthood. During the first year of life, babies’ brains double in size, and by the time they are six, their brain weight has tripled. These, it appears, are the crucial years for laying down brain cells and neural connections — pointing to the importance of providing both proper nourishment and intellectual stimulation in these early years. The study appeared in the October [2003] issue of Brain.

Nonetheless, I can report signs of cognitive decline in some areas at least, especially in an increase in those pesky “senior moments” when a word or a name just eludes me. Common enough.

I would say in my teaching I had two peaks – one around the late 20s to early 30s, the other in my fifties.

I took up blogging in my late fifties: has it arrested decline to some degree, or is it a sign of it? 😉


Posted by on March 17, 2009 in amazing, creativity, health, memory, personal, teaching


2 responses to “Decline

  1. Peter (Worldman)

    March 17, 2009 at 4:06 pm

    Well, I don’t have a large head, I am now 65 + and I hope that nobody is going to ask me to participate in a test. Because a failure might have an effect on my vanity 🙂

  2. Bruce

    March 19, 2009 at 1:20 am


    I’d better start shaking those pom poms for my dentrites. C’mon dendrites! Overcompensate for that downward curve!

    So many variables at any rate. Socio-economics and diet can cause huge fluctuations in these things. Sometimes I can feel a bit flustered and distracted.

    The last time I did an IQ test (a couple of years ago – can’t remember precisely which test it was but it was one of the ones that top out at 150), I got all the answers right, with 2 minutes to spare and I took a 5 min rest mid-way. Probably one of my more refreshed moments – I don’t feel I can operate like that a lot of the time.

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