ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

Intelligence IQ - Age at which Brain Starts to Deteriorate

Updated on November 23, 2015

The Soul is a Part of the Brain

The brain is one of the most important organs in humans. The brain is such an important organ that it is used to determine whether one is dead even after breathing has stopped. To some people, the soul is thought to be a part of the brain. If the soul can reside in the brain, then, it follows that the brain can also be invaded by bad spirits. This may be the reason why in many places the blind people are welcomed with both hands whilst the mentally ill are repelled at a distance.

Brain is Heavier in Men than in Women

The human brain per unit body weight is far much bigger than in any other animal. The average weight of an adult person’s brain is about 1.5 Kg. The brain is heavier and voluminous in men than in women. The average weight and volume of brain in men and women is as follows:

  1. In men: weight = 1.50 Kg, volume = 1.26 litres
  2. In women: weight = 1.40 Kg, Volume = 1.13 litres

This is in line with the fact that males are more muscular than females. It does not mean that men have a better cognitive performance than women. If anything, women may tend to have a slightly bigger brain per unit body weight.

Human brain grows at a very high rate during brain development. In early stages of development, the brain may add about 250,000 neurons every single minute. The brain’s glial cells are continuously dividing and multiplying.

Remembering Events That Happened Before Age 4

At age 20 -30 years, the brain has the maximum weight. Brain memory holding structures of hippocampus and amygdale develops within the first 10 years of life. This should explain why children will remember events from the age of 4 years but will fail to recall the same memories from their youngest years after they become adults.

Brain - Lateral surface of cerebral cortex
Brain - Lateral surface of cerebral cortex | Source

Age at which Brain Starts to Deteriorate

Humans have always wanted the age at which brain starts to deteriorate to be after the age of 60. But scientists, headed by Professor Archana Singh-Manoux, at University College London are suggesting that brain's ability to function can start to deteriorate as early as age 45.

‘Generative’ can basically be defined as when there are more cells forming in the brain than the cells dying per given period of time. ‘Degenerative’ can likewise be defined as when there are less cells forming in the brain than the cells dying per given period of time. Deterioration of the brain will therefore happen when the number of cells dying is more than the cells forming in the brain per a given period of time.

We Believe What We Can See

We humans have a tendency to believe what we can only see. What we can’t see is difficult to believe. We are able to quantify and accept what we can see. It is difficult to quantify the deterioration of our brains and in any case we do not want to hear of it.

Brain is an organ just like the eyes, skin, heart, etc. We can believe we are aging because we can see when the hair turns grey. We can believe we are aging when the eyesight starts deteriorating. We can believe we are aging when we start seeing wrinkles on our skins. These are all tangible signs that proof we are aging. But we don’t have many tangible signs to tell us our brains are aging, and in any case we don’t want to hear about it.

We can see and believe the prime age at which some of our muscles are working at maximum efficiency because we can see tangible proof. We can see and believe the age athletes are at their best because we can see them win in sports. We can see and believe the age footballers are at their best because we can see them play.

The graph below shows the age of 21 – 31 years as the age range at which most sportsmen are at the best.

Age of 21 – 31 years is the age range at which most sportsmen are at the best. Image Credit:
Age of 21 – 31 years is the age range at which most sportsmen are at the best. Image Credit:

Age at which Scientists Win the Nobel-Prizes

From research done by Stephan and Levin comparing the percentage performance of scientists and the age at which they won the Nobel-Prize, it was shown that the age at which most scientists won their Nobel prices is between age 31 and 40. This is as shown in the figure below which shows the percentage of price winners in chemistry, physics, medicine, and philosophy plotted against age. A marked deviation is in the case of philosophy where the age range of best performance is spread from 30 to 60 years. Why?

From the above we can conclude that humans’ intelligence is at maximum performance at between ages 31 – 40. And how long does the Norwegian Nobel Committee takes to spot one’s work and to award the price? If we assume it takes them 5 years, then the age at which humans’ intelligence is at maximum performance should drop to ages 26 -35. After age 35, the brain should start to deteriorate. This should not discourage you as the development of wisdom and experience continues to increase well past the age of seventy. Yes, wisdom, unlike intelligence, is more about philosophy.

Age at which most scientists won their Nobel prices is between age 31 and 40 years
Age at which most scientists won their Nobel prices is between age 31 and 40 years

Diminished Eyesight

Presbyopia is a condition where the eyes show a diminished ability to focus on near object with one’s age. Presbyopia happens due to loss of elasticity of the crystalline lens, loss of lens's curvature, and loss of power of the ciliary muscles. Presbyopia is caused by aging. The first symptoms of Presbyopia are noticed at the ages of 35 - 45. A child has an ability to focus 20 dioptres which decreases to 10 dioptres at age 25 years before going to a low of 1 diptres at age 60 and above.

So, at what age do most people start wearing glasses? Similarly, the first strand of grey hair is spotted at the age of 25 - 35 years in most people.

When are women most beautiful? At the age of 21-24 if you consider only body appearance. But if you consider body appearance and personality, women are most beautiful at the age of 28 - 31 years.

Now, this should tell us that some of our organs start failing at between the ages of 25 to 45. This should be no exceptional to the brain.

Brain Need to be Exercised

Brain, just like muscles for sportsmen, needs to be exercised to reach peak size for maximum performance. The best way to exercise your brain is to continue learning. Read a novel, a newspaper, an article, etc. The moment you stop learning, the brain will start to deteriorate – you just need to look at those who dropped out of school and stopped learning at the age of 14. If you stop learning, your handwriting, spelling and vocabulary will as well start to deteriorate with time.

Whilst the phrase “the average person develops only ten per cent of his/her latent mental ability” is a myth, it is important to note that the ages 21 – 40 are very critical. This is the age one has the highest probability of achieving maximum intelligence/IQ and success.


    0 of 8192 characters used
    Post Comment
    • DDE profile image

      Devika Primić 

      7 years ago from Dubrovnik, Croatia

      Wow! I had no idea the brain deteriorates by the age of forty, definitely a crucial point to never stop learning something new daily which is my goal.

    • Mellonyy profile image


      7 years ago

      Interesting and useful information! I didn't know that brain is heavier in men than in women. Voted up!

    • lorlie6 profile image

      Laurel Rogers 

      7 years ago from Grizzly Flats, Ca


      This is an amazing article and incredibly informative-Wow! I'm 55, a writer, reader, sociologist and philosopher-master's degrees-and feel I am now on top of my 'game'.

      You mentioned wisdom which does come with life experience-it seems that such wisdom is a part of aging, through constant vigilance and attention to human behavior. I love my ability (through education) to observe and then communicate such observations, whether watching my own behavior or that of others.

      You nailed this article in so many ways!

      Thank you,




    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at:

    Show Details
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the or domains, for performance and efficiency reasons. (Privacy Policy)
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)
    ClickscoThis is a data management platform studying reader behavior (Privacy Policy)