4D, Manning's index

Take a look at some of the international vocabulary + synonyms for the word ‘DIGIT RATIO‘:


The ‘DIGIT RATIO’ vocabulary in English language includes the words:
Finger ratio, 2D:4D ratio, 2nd to 4th ratio, 2th to 4th ratio, ring finger index finger ratio, finger length ratio, Manning’s index, Manning ratio, finger digit ratio, fingers ratio, finger size ratio


‘DIGIT RATIO’ synonyms in French language:
Indice de Manning


‘DIGIT RATO’ synonyms in Spanish language are:
Índice de Manning, ratio dedo de la mano


‘DIGIT RATIO’ synonyms in Porteguese language are:
Manning índice, dedo rácio


‘DIGIT RATIO’ synonyms in German language:
Finger-Verhältnis, Manning-Verhältnis


‘DIGIT RATIO’ synonyms in Dutch language:
Vinger ratio, vingerlengte ratio, Manning ratio


‘PALMISTRY’ synonyms in Rusian language are:
Соотношение палец

The Finger Book

The Finger Book

Hands up!

John Manning explains: “When we look at our fingers, we may think they are beautiful, ugly, refined, or stubby. We use them to eat, gesticulate, carry, point. But what do they tell us about our personalities?”
“Our fingers provide us with a wealth of evidence about how men and women differ, and how they are programmed before birth to show certain behaviour patterns and likelihood of getting certain diseases.”

“As a fascinating new book explains, the length of our ring and index fingers can greatly influence our personality, health and abilities.”

“The early growth of our ring finger is sensitive to levels of testosterone – the so-called “male hormone”, in the womb (as the testosterone receptors are more densely packed along the finger), and the longer our ring finger the more “masculine” we will turn out to be.”

“The relative length of our ring and index fingers – our “finger ratio” – therefore speaks volumes about the balance of maleness and femaleness of our body and brain.”

“A long ring finger is not universal, but characteristic of men. A long index finger is found in many men, but overall it is characteristic of women as a group.”

“After years of research, during which I conducted many experiments, I have concluded that there are many fascinating different things our fingers can tell us.”

READ FURTHER:

  • How your fingers reveal so much about you
  • Finger length news & research
  • If your ring finger is longer than your index finger...

    If your index finger is longer than your ring finger...

    Finger length in young boys related to early heart attack.

    The finger length in men related to early heart attack.

    Finger length & early heart attack:

    The length of a young boy’s finger may provide a clue as to whether he will be at risk of a heart attack in early adulthood. This is because these boys tend to have lower levels of the male sex hormone testosterone, which is known to protect against heart attack.

    Scientists at Liverpool University have established a link between the length of baby boys’ fingers and their chances of going on to have a heart attack at an unusually young age. They believe the link could provide doctors with a simple way to to spot potential heart disease victims at a very early age. The research shows that boys with shorter ring fingers tend to be at greatest risk.

    Lead researcher Dr John Manning told the BBC:

    “Males tend to have a relatively longer ring finger compared to the index finger than females.”

    “There is a relationship between the ratio between these two finger lengths and the age at heart attack of people who do have heart attacks.”

    Dr Manning and Dr Peter Bundred examined 151 male heart attack victims in Merseyside. They found the age range for heart attacks in men where the index finger was relatively long was 35 to 80 years of age, but in those with relatively long ring fingers it was 58 to 80.

    The research was published in the British Journal of Cardiology.

    An overview of the scientific sources which have found a link between finger length (high ‘digit ratio’: >1.0) and heart problems:

    * Endurance running and digit ratio (2D:4D): implications for fetal testosterone effects on running speed and vascular health. – 2007

    * The 2nd-4th digit ratio (2D:4D) and neck circumference: implications for risk factors in coronary heart disease. – 2006

    * The ratio of 2nd to 4th digit length: a new predictor of disease predisposition? – 2000

    Digit ratio related to early heart attack.

    Digit ratio concerns the 2th to 4th finger length difference.

    Digit ratio concerns the 2th to 4th finger length difference.

    A sexy woman in a bikini may sharpen the financial mind ... especially in men with low digit ratios!

    A sexy woman in a bikini may sharpen the financial mind ... especially in men with low digit ratios!

     

     

     

    How lingerie sharpens the financial mind in men with low ‘digit ratios’!

    According to recent news reports, the sight of lingerie or a sexy woman significantly impairs male decision making. But actually, the research under discussion … indicates the opposite!

    The study involved a well-researched financial task known as ‘the ultimatum game’, where one participant is given a sum of money (10 euros in this study) and has to decide how to split it with another. If the other participant accepts the split, both get to keep the money. If they don’t, no one gets anything!

    Researchers Bram van den Bergh and Seigfried Dewitte asked heterosexual male participants to play the game in pairs. Before they started the game, they were variously shown pictures of a sexy woman in bikini, landscapes, older women, younger women, or lingerie to handle.

    The best write-up of the study’s details is from Nature, who do point out that the results actually CONTRADICT the idea that sexy images makes men less rational!

    In the study, they actually made men more rational. The fact that men who saw sexy images were more likely to accept lower offers rather than reject them and get nothing at all, suggest that their short-term rationality was actually … enhanced!

    FULL ARTICLE:
    Lingerie sharpens the financial mind!

    Finger length related to autism.

    Autism research in the hands of children.

    Autism research in the hands of children.

    Finger Length & Autism:

    The world’s most famous ‘digit ratio’ research, John T. Manning, has begun examining autism too. He teamed up with Simon Baron- Cohen and Svetlana Lutchmaya from the University of Cambridge, who have used samples of amniotic fluid to directly measure the levels of hormones that babies are exposed to in the womb.

    When the children reached their first birthday, the researchers measured their vocabularies and ability to make eye contact. Poor language skills and an unwillingness to make eye contact are early hallmarks of autism. They found that babies who’d been exposed to high levels of testosterone in the womb fared the worst.

    “What we’re hoping to look at is whether finger ratios can be used as a proxy for hormones,” says Lutchmaya. Amniocentesis (sampling the amniotic fluic surrounding the unborn baby) is a risky procedure that only a few mothers choose to undergo, she says. But by measuring finger lengths instead, researchers can assess a random sample of children for possible early signs of impaired language and social skill development. Currently, they are checking the fingers of children for whom they have amniotic samples.

    Meanwhile, Manning and Baron-Cohen have looked at the finger ratios of 49 children with firm diagnoses of autism, 23 with a mild form of the disorder called Asperger’s syndrome, and their families. The researchers found that autistic children tended to have very low 2D:4D ratios. Interestingly, children with Asperger’s syndrome had ratios that fell between those of autistics and unaffected children. “It fits exceptionally well with the theory,” says Manning.

    Clearly genes play a role too in these conditions. But could fetal hormone levels explain other cognitive differences between the sexes? Janel Tortorice at Rutgers University in New Brunswick, New Jersey, thinks they may. She has measured finger ratios in 2D:4D ratio gay women and found that their hands were significantly different from those of heterosexual women-in fact, they tend to resemble those of heterosexual men.

    But she has also found differences in the way these women’s brains work. “They have more masculine fingers and more masculine cognition,” she says. On tests of spatial and verbal ability, lesbian volunteers perform more like men than heterosexual women, she says. If this can be confirmed by further studies, perhaps Manning’s most recent suggestion is not as outrageous as it sounds. He claims that musical talent, too, is nurtured in the womb.

    An overview of the scientific sources which have found a link between finger length (low ‘digit ratio’: 0.94) and autism:

    * The 2th to 4th ratio and autism – 2001 (PDF)

    * [Evaluation of the 2nd to 4th digit ratio in the patients with autism] – 2005 (Japanese study)

    * Differences in finger length ratio between males with autism, pervasive developmental disorder-not otherwise specified, ADHD, and anxiety disorders – 2006

    * Motion and form coherence detection in autistic spectrum disorder: relationship to motor control and 2:4 digit ratio – 2006

    Digit ratio related to autism.

    psychologist John T. Manning

    The Finger Book - author: John T. Manning

    Book Review:

    The Finger Book – author: Prof. John T. Manning, psychologist, University of Liverpool

    Publisher (Fabe and Faber, 2008) comment:

    “This book employs finger ratio to examine a group of questions about human behaviour, from sexuality, to musical ability, to predisposition to disease.”

    The publisher writes about John Manning’s book The Finger Book:

    “This book is about a simple measurement of the human hand: the ‘finger ratio’.

    What could fingers & sex possibly have in common? What does the shape of a child’s fingers reveal about future music talent? Why should professional footballers have longer ring fingers than other men?

    This book is about a simple measurment of the human hand. You may not have noticed that men tend to have longer ring fingers relative to their index fingers, and it turns out this tiny sex difference is highly revealing.

    John Manning, ‘a pioneer in this field’ (New Scientist) uses it to examine a dizzying group of questions about human behaviour, from sexuality, to music ability, to predisposition to disease. Controversial, but untainglingly clear and balanced, John Manning presents his cutting-edge research for the reader to consider.

    The finger length ratio (2D:4D) appears to tell us what happens to babies in the whomb, indicating the amount of testosterone and oestrogen to which each foetus is exposed. This early evens has, it seems, profound consequences in each of us. Provocative, arresting and direct, The Finger Book makes accessible a whole new area of evolutionary science, and poses many fruitful questions about what makes us as we are.”

    Digit ratio: A Pointer to Fertility, Behavior and Health

    Digit Ratio: A Pointer to Fertility, Behavior and Health

    Book Review:

    Digit Ratio: A Pointer to Fertility, Behavior and Health – author: John T. Manning

    Publisher: Rutgers University Press 2002

    Review by Michael Mills, Psychology Department, Los Angeles.

    Michael Mills writes about John Manning’s book Digit Ratio:

    “Take a look at your right-hand. Which of your fingers is longer: your ring finger, or your index finger? Surprisingly, a passing stranger who noticed a difference in length between these two fingers (and who had handy a copy of John Manning’s book Digit Ratio: A Pointer to Fertility, Behavior and Health) might infer some very personal characteristics about you. With no more data than that gleaned from a passing glance at your hands, a stranger might infer whether you are likely to have homosexual inclinations, are highly fertile, may eventually suffer from a heart attack or breast cancer, have musical aptitude or sporting prowess, and a surprisingly long list of other characteristics.

    …Females typically have index and ring fingers of about the same length. The ratio of index finger length to ring finger length is called the “2D:4D digit ratio,” or more simply, the “digit ratio.” Manning reports that, for males, the index finger is generally about 96 percent of the length of the ring finger, which gives an average digit ratio for males of .96.

    …Manning devotes separate chapters to explore the relationship between digit ratio and a variety of characteristics, including assertiveness and attractiveness (chapter 3), reproductive success (chapter 4), hand preference, verbal fluency, autism, and depression (chapter 5), health and disease (chapter 6), homosexuality (chapter 7), musical aptitude (chapter 8 ) and sports aptitude (chapter 9). A brief summary Manning’s findings (some of which he notes are quite preliminary) is presented in the table below.”

     

    Low 2D:4D ratio

    High 2D:4D ratio

    Males

    * More fertile
    * Higher lifetime reproductive success
    * More aggressive and assertive
    * Greater proclivity toward homosexuality/bisexuality
    * Higher musical and sports aptitude
    * Lower SES (?)

    * Higher risk of early heart disease

    Females

    * Greater proclivity toward homosexuality/bisexuality
    * More aggressive and assertive

    * More fertile
    * Higher lifetime reproductive success
    * Higher risk of breast cancer

    Emma Nelson

    Emma Nelson studies

    ‘Digit ratio’ in non-human primates:

    ‘Digit ratio’ research is not limited to the human hand. Emma Nelson from Department of Archaeology, University of Liverpool is one of the key-researchers who studies ‘digit ratio’ in the hands of primates.

    The major focuss in Emma Nelson’s ”digit ratio’ research in primates is:

    “Using digit ratios (2D:4D) to investigate social systems in anthropoids; implications for the study of the evolution of hominin sociality.”.

    Variation in non-human primate 2D:4D is currently unknown. One of the aims of this project is to map differences in mean 2D:4D within and between non-human primates species.

    Digit ratio in non-human primates

    digit ratio

    A short history of major the developments in the concept of ‘digit ratio’:

  • In 1888 antropologist and biologist Dr. Frank Baker noticed that the index finger is usually short than the ring finger:
  • More than a hundred years ago, a very entertaining paper concerning various customs and superstitions associated with the hand – titled: Anthropological Notes on the Human Hand (1888) – was presented to the Antropological Society of Washington by Frank Baker, Professor of Anatomy at the University of Georgetown. Following some fascinating tales, and a debunking of palmistry, he concluded by discussing the comparative lengths of the digits, and noted that the second (index) finger is usually shorter than the fourth (ring) finger.

  • In 1930 antropologist Ruggles George noticed a sex difference in the index finger and the ring finger:
  • Some years later R. George described in a paper – titled: Human Finger types (1930) – a sex difference in the distribution of finger length ratios in that males are more likely to show the 2 < 4 pattern (i.e. a longer ring finger relative to the index finger), while females are more likely to show the opposite pattern (2 > 4).

  • In 1952 antropologist V.R. Phelps discovered that finger length is stable throughout life:
  • Two decades later the sex difference findings reported by George (1930) were confirmed in the work of V.R. Phelps – titled: Relative index finger length as a sex-influenced trait in man (1952) – noting that such differences were observed in foetuses, and then appeared to be stable throughout life.

    Psychologist Glenn Wilson

    Psychologist Glenn Wilson

    * In 1983 Psychologist Glenn Wilson introduced the word ‘digit ratio’:

    Dr Glenn Wilson of King’s College, London published a study – titled: ‘Finger length as an index of assertiveness in women‘ – which introduced the 2D/4D ‘digit ratio’ as a marker of exposure to prenatal testosterone + examining the correlation between assertiveness in women and their digit ratio. This was the first study to examine the correlation between digit ratio and a psychological trait within members of the same sex.

    Psychologist John T. Manning

    Psychologist John T. Manning

    * In 1998 Psychologist John T. Manning presented a link between ‘digit ratio’ and testosterone + sperm counts:

    This link was described by Manning in a study – titled: ‘The ratio of 2nd to 4th digit length: a predictor of sperm numbers and concentrations of testosterone‘.

    'Digit ratio' - the book

    Digit Ratio - the book

    * In 2002 Psychologist John T. Manning presented the book ‘Digit ratio’:

    Psychologist John T. Manning presented his first book about the 2D:4D ratio – titled: ‘Digit ratio: A Pointer to Fertility, Behavior and Health‘.

    In this book Manning presents a first overview of the digit ratio research which has been presented uptill the year 2002.

    The finger book

    The finger book

    * In 2008 Psychologist John T. Manning presented the book ‘The finger book’:

    Psychologist John T. Manning presented his first book about the 2D:4D ratio – titled: ‘The finger book‘.

    Quote from New Scientist:

    “According to evolutionary psychologist John Manning, who has spent years researching the secrets they betray, your digits reveal all sorts of things, from your sexuality to whether you are socially disadvantaged or likely to suffer a heart attack. They even, as the legend goes, give away the size of a man’s penis.”

    Take a look at your feet…

    What do you see? Most of us will see 5 toes … and very likely your inner toe will be the longest, the largest, AND the biggest! As a matter of fact, this a typical characteristic of the human foot!

    Now, let’s take a look at the feet of primates… (see the picture below):

    The primate foot and the human foot.

    Do you see the difference? The foot of these primates show quite a different picture: for, the inner toe is always the lowest set toe! This is a typical characteristic of the primate foot. And often the length of the inner toe does not pass the length of the other toes. 

    Another rather remarkable aspect is the fact that the ‘big toe’ of primates (the inner toe) shows quite some similarities with the thumb of our hands.

    These typical characteristics in human and primate foot were already described in 1920 in the work PRINCIPLES OF ANATOMY presented by Frederic Wood Jones. Wood Jones described these characteristics through the concept: DIGITAL FORMULA.

    The typical ‘digital formula’ for the human foot is: 1>2>3>4>5 – in the typical human foot the inner toe (toe 1) is usually the longest, and the little toe (toe 5) is usually the shortest.

    However, the typical primate foot is characterised by the so-called ‘simian digital formula’: 3>4>2>5>1 – in the typical primate foot the middel toe (toe 3) is usually the longest, and the ‘inner toe’ (toe 1) the shortest!

    Notice: Jones’ describes on page 30:

     “… the digital forumula*, and it must be remembered that such a formula does not express the relative length of the digits, but the relative projection of the tip of the digits from the extremity of the limb”.

    The ‘human digit formula’ for our hands…

    Interestingly, the typical ‘digital formula’ for the primate foot resembles the typical ‘simian digital formula’ for the primates hand: 3>4>2>5>1 – you see the confirmation in the picture below!

    How to measure digit ratio?

    As a matter of fact, the ‘digital formula’ of the human hand often resembles the typical ‘simian digital formula’: 3>4>2>5>1 – especially in the hand of human males! But also the hands of human females can often be characterized by the ‘simian digital formula’, however more often the hands of women can be described with the ‘human digital formula’: 3>2>4>5>1.

    The difference is that in human males the ring finger is more often larger than the index finger (or: pointer finger) – which resembles the  ‘simian digital formula’! In human females more often the index finger is longer than the ring finger – which resembles the ‘human digital formula’! These principles are visible in the picture below:

    Digit ratio in the male and the female hand

    The ‘digit ratio’ formula!

    However, both in human males and females the length difference between the index finger (digit 2) and the ring finger (digit 4) is often very small. And therefore the ‘ratio’ between the length of those fingers is often close to ‘one’ (1.00) – when both fingers have the same length, the ‘ratio’ between the 2 fingers is exactly ‘1.00’.

    Because of this situation scientists around the world are using the concept ‘digit ratio’ to study the relative length difference between the index finger (digit 2 = 2D), and the ring finger (digit 4 = 4D), which results in the formula: ‘digit ratio’ = 2D:4D.*

    * One should notice here that the concept of Wood Jones ‘digital formula’ is related to “… projection of the tip of the digits from the extremity of the limb” -see the 3th picture in this blog post). However, the ‘digit ratio’ is related to the absolute length difference between the index finger and the ring finger – see the picture below.

    How to measure digit ratio?