Outside influences such as low motivation or high anxiety can occasionally lower a person's IQ test score. So, up to approximately 10 IQ points difference in scores can be accounted for by measurement error and performance variability, but stressors can potentially result in larger differences.
Investigations using advanced brain imaging reported a reduction in hippocampal volume in individuals with long-term Post Traumatic Stress Disorder (PTSD). It is thought that this shrinkage is responsible for the observed memory problems. Also chronic and intense stress has negative effects on intelligence.
Interestingly, there was no significant correlation between stress and IQ, although stress was significantly correlated with EI and EI was significantly correlated with IQ. The correlations between stress and EI.
Relatively high anxiety in patients with GAD predicted high IQ whereas relatively low anxiety in controls also predicted high IQ. That is, the relationship between anxiety and intelligence was positive in GAD patients but inverse in healthy volunteers.
Stress. A recent theory suggests that early childhood stress may affect the developing brain and cause negative effects. Exposure to violence in childhood has been associated with lower school grades and lower IQ in children of all races.
However, there is also a lot of research that shows that depression actively leads to a detrimental development of the frontal lobe, ultimately affecting your intelligence and lowering your IQ because you're simply too depressed to think straight, or can't complete certain cognitive tasks anymore.
Thinking excessively does not have any impact on the ridges and grooves so it does not reduce intelligence. However, a person might seem unintelligent if their ability to think properly is hampered. Even if one thinks too much, they will be fine as long as their thoughts remain consistent.
Studies have also found that higher IQ is associated with more mental illness, including depression, anxiety, and bipolar disorder.
Intelligence and anxiety may have evolved together as mutually beneficial traits, research finds. This may help to explain why people with a high IQ also tend to have higher levels of anxiety. The benefit may be that intelligence allows people to better imagine what might go wrong.
Less sleep lowers IQ scores
The daily decline is approximately one IQ point for the first hour of sleep loss, two for the next, and four for the next. After five successive days of sleeping less than you need, your IQ can be lowered by up to 15 points.
Persons who developed PTSD following either assaultive violence or other event type had lower IQ scores at age 6 than those who did not develop PTSD, according to these results.
Some tests may be more reliable than others, but it is also possible that IQ scores can change over time. Many factors can affect IQ test scores, including access to education, cultural factors, overall health, and nutrition.
Someone with a low, average, or high IQ can develop depression. It is thought that measures of intelligence may influence a future psychiatric diagnosis. Because there are many risk factors for depression, including trauma, chronic illness, and genes, a person should consult a doctor if they are experiencing symptoms.
Mental age and IQ are related, but not the same thing. Mental age is a measure of a person's intellectual development compared to their peers, while IQ is a score based on standardized tests designed to measure intelligence.
People with high intelligence tend to share this quality. Intelligent people tend to be better behaved and less aggressive, research reveals.
In fact, studies show that highly intelligent people are vulnerable to developing mood disorders, like depression and bipolar disorder. As they are very goal-oriented, highly intelligent individuals try to “create” their own happiness.
New research suggests that highly intelligent people find it tricky to focus their minds because they have so many brilliant ideas constantly whizzing around their brains (#geniusproblems).
In healthy volunteers, total brain volume weakly correlates with intelligence, with a correlation value between 0.3 and 0.4 out of a possible 1.0. In other words, brain size accounts for between 9 and 16 percent of the overall variability in general intelligence.
While they might have high standards and big picture concerns, research shows that people with high IQs are actually more likely to be happy; data from the research showed that people with the highest IQs were much happier than those with the lowest IQs.
But genetics can explain the wide range of possible IQs too because so many different genes are involved in developing and running a brain. It is possible, for example, to inherit all the higher IQ genes from each parent and leave the lower IQ ones behind. Now the child will be brighter than the parent.
Can IQ change with age? Yes. However, there is heavy debate over exactly how IQ and intelligence change with age. Studies have demonstrated that a person's fluid intelligence tends to decrease starting in their late 20s, while their crystallized intelligence tends to increase as they grow older.
115 to 129: Above average or bright. 130 to 144: Moderately gifted. 145 to 159: Highly gifted. 160 to 179: Exceptionally gifted. 180 and up: Profoundly gifted.
Tall signs of intelligence
The conclusion comes from a study of the DNA of 6,815 people. Of course, there are still people who are short and intelligent, plus those who are tall and dim. But, on average, there is a small association between being taller and having higher intelligence.