After various studies in the past had already suggested that 2D:4D digit ratio could be linked with the Big Five personality dimension Extraversion / Introversion, a new experimental study shows how the finger ratio combined with hand shape produces highly significant results.

The picture above displays a schematic presentation of the results: e.g. the ‘+’ and ‘-‘ signs show the proportional tendencies in the hands of Extraverts and Introverts. Details regarding the underlying results are presented in the article:

Extraversion associated with 2D:4D digit ratio, finger length & hand shape!

The right hand of Barack Obama!

Barack Obama.

The right hand of George W. Bush!

George W. Bush.

The right hand of Bill Clinton!

Bill Clinton.

The right hand of George H.W. Bush!

George H.W. Bush.

The right hand of Ronald Reagan!

Ronald Reagan.

The right hand of Jimmy Carter!

Jimmy Carter.

The right hand of Gerald Ford!

Gerald Ford.

The right hand of Richard Nixon!

Richard Nixon.

The right hand of Lyndon Johnson!

Lyndon Johnson.

Presidential palm readings: US presidents have a low 2D:4D finger ratio!

Earlier this year TIME presented a photo essay of the hands of the last 9 US presidents. Let’s take a look at the finger ratio of their right hand!

Barack Obama’s finger ratio:

Barack Obama’s right hand clearly shows a very low ‘2D:4D digit ratio’. An earlier report on his left hand presented a ‘2D:4D digit ratio’ estimation close to 0.90-0.92, and various photos indicate that the same zone is indicated for his right hand.

NOTICE: though his inauguration photo appears to present a slightly higher ratio – but in that photo his fingers are obviously not ‘stretched’ and therefore that photo should be ignored).

George W. Bush’s finger ratio:

His inauguration photo shows that George W. Bush’s right hand shows a low ‘2D:4D digit ratio’, which is likely close to 0.90.

Bill Clinton’s finger ratio:

There are not many photos available that are suitable for measuring Bill Clinton’s finger length but various photos indicate that Bill Clinton’s ‘2D:4D digit ratio’ is close to 0.96-0.97, which could be described as normal for a white male.

George H.W. Bush’s finger ratio:

His inauguration photo shows that George H.W. Bush’s right hand shows a low ‘2D:4D digit ratio’, which is likely close to 0.95-0.96.

Ronald Reagan’s finger ratio:

Ronald Reagan’s right waving hand shows clearly a very low ‘2D:4D digit ratio’, which is likely close to 0.90.

Jimmy Carter’s finger ratio:

Jimmy Carter’s right waving hand shows also a very low ‘2D:4D digit ratio’, which is likely close to 0.90.

Gerald Ford’s finger ratio:

Gerald Ford’s inauguration photo shows that his ring finger is (much) longer than his index finger – confirmed by his right hand waving photo – but in his case it’s hard to make a more detailed estimation beyond that his finger length ratio can definitely be described as: ‘below average’.

Richard Nixon’s finger ratio:

Richard Nixon’s right hand waving photo shows that his ring finger is definitely longer than his index finger: ‘below average’ and close to 0.95-0.96.

Lyndon Johnson’s finger ratio:

Lyndon Johnson’s inauguration photo shows that lowest ‘2D:4D digit ratio’ of all presidential men – likely below 0.89.


Five out of the last nine US presidents (Obama, G.W. Bush, Reagan, Carter & Johnson) have a very low digit ratio – close to 0.90 or even lower!

Only in Clinton’s right hand the ‘2D:4D finger ratio’ can be described as normal.


Famous hands: the hand of celebrities!
More news reports related tothe  ‘2D:4D digit ratio’
The hands of Barack Obama: his finger length
What does the hand of a celebrity reveal?

Is 2D:4D finger ratio research misleading?

Is 2D:4D finger ratio research misleading?

Is finger ratio research misleading / deceptive?

This week Czech researchers presented a revision of their earlier reported results: “previously published results on the 2D:4D ratio are biased by its covariation with finger length”. But the Czech researchers also reported very explicitely: “We do not claim that the previous results for the finger length ratio are wrong”.

What can we conclude from the latests step in finger ratio research?

What are the essentials of the Czech research? The Czech researchers claim that the fundamentals of the male-female 2D:4D finger length ratios can be related to male-female differences in finger length. Men usually have longer fingers (larger hand) than women – and there appears to be a negative correlation between finger length in general and the 2D:4D finger ratio.

The Czech research was presented under the title: ‘Differences in the 2nd to 4th digit length ratio in humans reflect shifts along the common allometric line’ – some quotes from the researchers about their finger ratio findings:

“Most studies agree that 2D:4D is sexually dimorphic.”

“Sexual differences in 2D : 4D are mainly caused by the shift along the common allometric line with non-zero intercept, which means 2D : 4D necessarily decreases with increasing finger length, and the fact that men have longer fingers than women.”

“We do not claim that the previous results for the finger length ratio are wrong”

“We conclude that previously published results on the 2D : 4D ratio are biased by its covariation with finger length. We strongly recommend regression-based approaches for comparisons of hand shape among different groups.”

The fingers of Albert Einstein.

The fingers of Albert Einstein.

Albert Einstein has a ‘2D:4D finger ratio’ of 0.93:

In 1930 a German hand reader, Marianne Raschig, has taken the handprints of Albert Einstein (he was born in Germany) and one year later they were presented in her book: ‘Hand und Persönlichkeit’.

Almost 80 years later the ‘2D: 4D digit ratio’ (ratio between the index finger & ring finger) is now measured from the high quality handprints.

Einstein had a ‘2D:4D finger ratio’ of: 0.93

The high quality handprints of Albert Einstein can found in the article:
Handprints: the hands of Albert Einstein

The picture below is also taken from the German book. The results of a detailed measurement procedure (taken by a Dutch psychologist) indicates that the ‘2D:4D digit ratio’ is for both hands: 0.93.

This is especially interesting because researchers at Cambridge and Oxford universities believe Albert Einstein displayed signs of autism (Asperger syndrome). Earlier research on finger length & autism has indicated that a low digit ratio (0.94 or lower) highers the chance for the presence of autism!

Therefore it seems fair to conclude that the fingers of Einstein provide evidence which support the perceptions of the UK researchers who suspect that Albert Einstein had autism!

The handprints of Albert Einstein.

What can we learn from our fingers & finger length?
The curved little finger & autism
Finger length (low digit ratio) related to autism
More fingerprints news
Global news about hand reading & palmistry

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.”


  • 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.

    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.”