Average intelligence? How do you rate?

[Guest]

If intelligence is normally distributed, then 50% of the population are below average intelligence. What you're using to define and measure intelligence is the important point though.

[SpeedwayDan 10]

i've found that some of the most intelligent people seem to lack common sense.

 

I do agree that IQ tests aren't the best way of measuring intelligence, iw as reading an article about this the other day, someone had launched a new test which alot of so called experts had all agreed that it would provide a better measure of your intelligence.

[blueaura 10]

A mean (average) is a measure of dispursion across a number range.

 

If you take a fair sample of 100 people with IQ's ranging from 60 - 160 the average is 110, statistically there will always be 50% below average and 50% above average if a fair sample is used.

 

So yes, 50% of people are below average intelligence if you look at it purely as a statistic.

 

As Hecate says what is important is how they are measuring intelligence and how they arrive at that statistic.

[medusa 16]

On a median measure 50% will be below average?

 

On a median measure, the 'average' is an arbitrary figure which is found merely by knowing the difference between the highest and lowest figure- it doesn't tell you anything at all about the distribution of the rest of the population of the poll.

 

Similarly, with a mode average, the 'average' is decided by the most population on the same level- and by definition that means that there will be less than 50% on a lower figure than that, because there's a significant portion of the population on the same level as the average.

[Guest]

On a median measure, the 'average' is an arbitrary figure which is found merely by knowing the difference between the highest and lowest figure- it doesn't tell you anything at all about the distribution of the rest of the population of the poll.

 

Similarly, with a mode average, the 'average' is decided by the most population on the same level- and by definition that means that there will be less than 50% on a lower figure than that, because there's a significant portion of the population on the same level as the average.

For a normally distributed variable like intelligence (as measured by IQ), mean, mode and median are the same, and are found at the centre point of the normal distribution.

[medusa 16]

For a normally distributed variable like intelligence (as measured by IQ), mean, mode and median are the same, and are found at the centre point of the normal distribution.

 

Surely that depends on how you measure intelligence?

[upinwath 10]

As far as IQ goes that puts me above average but what's a number when you see above average people taking drugs or getting smashed out of their brains ?

Being bright is no measure of how stupid you can be.

Look at some of my posts.

[Guest]

Surely that depends on how you measure intelligence?

Which is why I said as measured by IQ .

 

Then again, if other variables like 'common sense' are normally distributed within the population, you'd have a similar pattern for the measures of central tendency and dispersion.

[Alastair 12]

50% of anything is below average, though the figure rises to 99% for Rotherham.

[angle20 10]

On a median measure, the 'average' is an arbitrary figure which is found merely by knowing the difference between the highest and lowest figure- it doesn't tell you anything at all about the distribution of the rest of the population of the poll.

 

Similarly, with a mode average, the 'average' is decided by the most population on the same level- and by definition that means that there will be less than 50% on a lower figure than that, because there's a significant portion of the population on the same level as the average.

 

I'm not sure about the median being 'arbitrary'. If you stand all your items in a line in order of whatever it is that is being measured, the median is the one smack bang in the middle. For this reason many statisticians regard the median as being the most representative measure of the average.

 

The mode is the most frequently occurring or single most common item but it is, as you suggest, not necessarily a good guide to the distribution of the rest of the population.

 

The problem with the mean (the total value of the items divided by their number), which crops up in things like 'average wage' and 'average house price' is that it can be skewed by a relatively small number of items at one end of the scale (usually upper) - as with city bankers or houses in Whirlow.

[Cyclone 10]

Apparently 50% of the population are below average intelligence.

 

It's an interesting statistic. Do you agree?

 

Mean, mode or median? You have to be clear when talking about averages.

 

The IQ of 100 is defined as the 'average', so the scale is adjusted when necessary to ensure that 100 is always the average.

[Cyclone 10]

A mean (average) is a measure of dispursion across a number range.

 

If you take a fair sample of 100 people with IQ's ranging from 60 - 160 the average is 110, statistically there will always be 50% below average and 50% above average if a fair sample is used.

 

So yes, 50% of people are below average intelligence if you look at it purely as a statistic.

 

As Hecate says what is important is how they are measuring intelligence and how they arrive at that statistic.

 

Assuming that the distribution across that range is random, which it may not be.

 

If the probability curve has a bias then the mean may be moved towards one end or the other...