can iq decrease?

Answer 1

if you smoke a lot of pot

Answer 2

The Flynn effect
Main article: Flynn effect
The Flynn effect is named after James R. Flynn, a New Zealand based political scientist. He discovered that IQ scores worldwide appear to be slowly rising at a rate of around three IQ points per decade (Flynn, 1999). Attempted explanations have included improved nutrition, a trend towards smaller families, better education, greater environmental complexity, and heterosis (Mingroni, 2004). However, tests are renormalized occasionally to obtain mean scores of 100, for example WISC-R (1974), WISC-III (1991) and WISC-IV (2003). Hence it is difficult to compare IQ scores measured years apart.

There is recent evidence that the tendency for intelligence scores to rise has ended in some first world countries. In 2004, Jon Martin Sundet of the University of Oslo and colleagues published an article documenting scores on intelligence tests given to Norwegian conscripts between the 1950s and 2002, showing that the increase in scores of general intelligence stopped after the mid-1990s and in numerical reasoning subtests, declined.[20]

Thomas W. Teasdale of the University of Copenhagen and David R. Owen of Brooklyn College, City University of New York, discovered similar results in Denmark, where intelligence test results showed no rise across the 1990s.[21]

Indications that scores on intelligence tests are not universally climbing have also come from the United Kingdom. Michael Shayer, a psychologist at King's College, University of London, and two colleagues report that performance on tests of physical reasoning given to children entering British secondary schools declined markedly between 1976 and 2003.[22]


[edit] Group differences
Among the most controversial issues related to the study of intelligence is the observation that intelligence measures such as IQ scores vary between populations. While there is little scholarly debate about the existence of some of these differences, the reasons remain highly controversial both within academia and in the public sphere.

Answer 3

As we age alot of our Normal Body Functions decrease. Our IQ is not only one of them. We will suffer hair Loss or thinning, muscle Loss, and certainly Memory Loss. Our eye sight will start to diminish and alot will need glasses or contacts. We can do what we can to stay in good physical shape, but we are limited..

Answer 4

Sure...but it usually due to a stroke, car accident, head trauma or something of the like. If you took a test say 2 years ago and get a 160 and then another now and get say 130 then most likely you are distracted and need to retake the test.

Answer 5

Yes, it can as the influence of your environment. Or Tv. Or boring life. Even life completely without stress can bring you to decrease as brain don't work actively.

Answer 6

yes from head injury, drugs, just any brain damage even ageing can cause your iq to decrease

Answer 7

yes. if u train with weights and do not consume enough carbohydrates your muscles will take it from brains, so u will become dumber. that's why it is a common joke that bodybuilders can't do math. cos they really can't before competitions

Answer 8

yup, it decreases with age, and drugs i think aswell?

Answer 9

Short answer - yes
Remember the saying "if you dont use it you lose it" well thats true.

Answer 10

I am certain of it....the older I get the dumber I seem.

Answer 11

I suppose it can if you do not keep educating yourself, and keep sharp, if you are not using it, then you are not keeping it up there.