Publications: Hands & Dermatoglyphics

Dermatoglyphics, the ridged skin of the hands and feet, are one of the best available diagnostic tools in genetic disorders. Studies on dermatoglyphics and hands have received little media attention with the exception of Manning's research on finger digits and sexuality. This is probably why the public still tends to associate hands with palmistry and fortune telling rather than the object of scientific interest. Thousands of scientific studies on hands have been undertaken over the years, mostly on the genetic basis of certain medical disorders. A more recent trend has been to look at the genetic basis of certain psychological disorders or characteristics, by studying the dermatoglyphics of the hand, and even more recently, finger digit ratios. Very few studies observe the variations of the palmar creases, although significant increases in unusual palm creases have been found in relation to a number of psychological disorders/conditions. While the origin of these hand creases remains a mystery, it has been confirmed that they are not created by folding of the hands, but rather under genetic and other, less understood, influences in foetal development.

The best place to look for studies on hands is PubMed of the US National Library of Medicine.

• PubMed: http://www.ncbi.nlm.nih.gov/entrez
  (some keywords: dermatoglyphics, fingerprints, digit ratio, palmar crease, flexion crease, simian crease).

Categories

• Alcoholism - 4 articles, 1977-1987
• Attention-deficit hyperactivity disorder (AD/HD) - 4 articles, 1977-2006
• Autism - 8 articles, 1977-2003
• Dementia - 6 articles, 1985-1992
• Depression - 5 articles, 1977-2004
• Dyslexia - 1 article, 1988
• Psychosis - 7 articles, 1970-2002
• Schizophrenia - 19 articles, 1994-2005
• Sexual Orientation - 13 articles, 1994-2006

• Other articles of interest - 4 articles
• Significance of hand creases (flexion creases) - 13 articles, 1973-2002

Alcoholism

• 1987 Genetic constitution differences in patients with various forms of alcoholism
• 1981 Papillary pattern of male chronic alcoholics
• 1978 Furrows and dermal ridges of the hand in patients with alcohol embryopathy - Palmar creases and dermal ridge patterns.
• 1977 Possible genetic predisposition for alcohol addiction.

Attention-deficit hyperactivity disorder (AD/HD)

• 2006 Attention-deficit hyperactivity disorder and fluctuating asymmetry in another college sample. - significant correlation found for both sexes.
• 2003 Attention-deficit hyperactivity disorder (AD/HD) and fluctuating asymmetry (FA) in a college sample: an exploratory study. - relation found in males only
• 1982 Dermatoglyphics of hyperactive males. - no relationship found
• 1977 Do hyperactive children tend to have abnormal palmar creases? Report of a suggestive association. - no abstract

Autism

• 2003 Dermatoglyphs of digito-palmar complex in autistic disorder: family analysis. --> Direct link to article.
• 2001 The 2nd to 4th digit ratio and autism.
• 1993 Ridge hypoplasia and ridge dissociation: minor physical anomalies in autistic children
• 1990 Dermatoglyphic analysis of autistic Basque children
• 1990 Dermatoglyphic study in autistic children and controls.
• 1979 A comparative dermatoglyphic study of autistic, retarded, and normal children.
• 1979 Fingerprints and laterality preferences of early-onset autism
• 1977 A dermatoglyphic study of autistic patients.

Dementia

• 1992 Dermatoglyphic patterns in dementia of the Alzheimer type: a case-control study.
• 1988 Digital and palmar dermatoglyphics in dementia of the Alzheimer type.
• 1988 Dermatoglyphic patterns in senile dementia of Alzheimer's type.
• 1986 Dermatoglyphic patterns in Alzheimer's disease.
• 1986 Fingerprint pattern differences in early- and late-onset primary degenerative dementia. - Patients with an early, but not those with a late, onset of dementia had significantly more ulnar loops than the control group.
• 1985 Fingerprint patterns in Alzheimer's disease. - significantly increased frequency of ulnar loops.

Depression

• 2004 Depression in men is associated with more feminine finger length ratios - links directly to full article
• 1999 Dermatoglyphic analysis in bipolar affective disorder and schizophrenia--"continuum of psychosis" hypothesis corroborated?
• 1986 Familial pure depressive disorder versus sporadic depressive disorder: a dermatoglyphic study. - no abstract
• 1980 A comparative study of quantitative dermatoglyphics in depressive neurosis and manic-depressive psychosis. - no abstract
• 1977 Dermatoglyphics in unipolar depression. Relevance of family history. - no abstract

Dyslexia

• 1988 Palmar dermatoglyphics of dyslexia

Psychosis

• 2002 Further evidence that congenital dermatoglyphic abnormalities are associated with psychosis: a twin study.
• 2003 Directional and fluctuating asymmetry in finger and a-b ridge counts in psychosis: a case-control study.
• 2000 Congenital dermatoglyphic malformations and psychosis: a twin study. - link to full article.
• 1997 Dermatoglyphic abnormalities in psychosis: a twin study - full text
• 1980 Manic-depressive psychosis and schizophrenia: a dermatoglyphic study
• 1974 Dermatoglyphics of childhood psychosis: a family study. - no abstract.
• 1970 Dermatoglyphic findings on a group of psychotic children.

Schizophrenia

• 2005 Understanding putative risk factors for schizophrenia: retrospective and prospective studies.
• 2005 Dermatoglyphic anomalies and neurocognitive deficits in sibling pairs discordant for schizophrenia spectrum disorders.
• 2005 Extralimital triradii as a putative marker of schizotypy.
• 2005 Dermatoglyphics and Schizophrenia: a meta-analysis and investigation of the impact of obstetric complications upon a-b ridge count.
• 2005 Dermatoglyphics and schizophrenia: findings from the Edinburgh high risk study.
• 2005 Dermatoglyphic anomalies in psychometrically identified schizotypic young adults.
• 2004 Digit length pattern in schizophrenia suggests disturbed prenatal hemispheric lateralization.
• 2004 Neurological soft signs and dermatoglyphic anomalies in twins with schizophrenia.
• 2002 Dermatoglyphics and schizophrenia: a Mexican study. - no abstract
• 2001 Differentiating between low and high susceptibility to schizophrenia in twins: the significance of dermatoglyphic indices in relation to other determinants of brain development.
• 2001 Dermatoglyphic fluctuating asymmetry and atypical handedness in schizophrenia.
• 2001 Is reduced dermatoglyphic a-b ridge count a reliable marker of developmental impairment in schizophrenia?
• 2000 a-b ridge count and schizophrenia. - no abstract
• 2000 Congenital dermatoglyphic malformations and psychosis: a twin study.
• 1999 Dermatoglyphic analysis in bipolar affective disorder and schizophrenia--"continuum of psychosis" hypothesis corroborated?
• 1999 Relevance of sequential development of dermatoglyphics to schizophrenia
• 1998 Dermatoglyphic analysis in borderline personality disorder and schizophrenia--results of a Croatian study.
• 1996 Dermatoglyphic a-b ridge count as a possible marker for developmental disturbance in schizophrenia: replication in two samples.
• 1994* Further evidence for anomalies in the hand-prints of patients with schizophrenia: a study of secondary creases.

Sexual Orientation

• 2006 2nd to 4th digit ratio (2D:4D) and number of sex partners: evidence for effects of prenatal testosterone in men.
• 2005 Digit ratio (2D:4D) in homosexual and heterosexual men from Austria.
• 2005 Photocopies yield lower digit ratios (2D:4D) than direct finger measurements.
• 2003 2nd to 4th digit ratio and a universal mean for prenatal testosterone in homosexual men.
• 2003 Are 2D:4D finger-length ratios related to sexual orientation? Yes for men, no for women.
• 2003 Sexual orientation and the 2nd to 4th finger length ratio: evidence for organising effects of sex hormones or developmental instability?
• 2003 Sex role identity related to the ratio of second to fourth digit length in women.
• 2002 Dermatoglyphics, handedness, sex, and sexual orientation.
• 2002 Differences in finger length ratios between self-identified "butch" and "femme" lesbians.
• 2001 Finger-length ratios, sexual orientation and offspring sex ratios. - no abstract
• 2001 The ratio of 2nd to 4th digit length: a proxy for testosterone, and susceptibility to HIV and AIDS?.
• 2000 Finger-length ratios and sexual orientation - no abstract, published in Nature
• 1994 Dermatoglyphic asymmetry and sexual orientation in men.

Studies showing a genetic influence in the development of hand/flexion creases

• 2002 Supernumerary digital flexion creases: an additional clinical manifestation of Alagille syndrome.
  - "Supernumerary digital flexion creases have been identified in 16/46 (35%) of AGS probands...Supernumerary digital creases have been reported in less than 1% of the general population...Hypotheses regarding the origin of flexion creases are discussed."
• 2001 Dermatoglyphics and abnormal palmar flexion creases as markers of early prenatal stress in children with idiopathic intellectual disability.
  - "A significant increase of abnormal palmar flexion creases , were found in IID (idiopathic intellectual disability) cases in comparison to controls."
• 2000 Congenital dermatoglyphic malformations and psychosis: a twin study. - link to full article.
  - "Examples of abnormal palmar flexion creases are the Simian line, the Sydney line, clear broken proximal and distal palmar creases, and very rudimentary creases...The risk of an abnormal palmar flexion crease was 36.0% in the discordant affected twins (N=9), 32.4% in the concordant affected twins (N=11), and 16.0% in the discordant nonaffected twins (N=4)."
• 1991 Embryologic development of flexion creases.
  - "Scientific interest in the palmar, plantar, and digital flexion creases has been related mainly to their aberrations in numerous congenital malformations and other medical disorders...While the timing of development of the flexion creases has now been established, their origin is less well understood. Both primary genetic determination and development secondary to flexion function have been suggested as the mechanisms underlying the crease development. The evidence offered has been mostly indirect, related to the timing of the onset of the fetal hand movement and the crease aberrations in malformed hands and fingers. More detailed studies, preferably including experimental designs in nonhuman fetuses, will be necessary to resolve the question of the origin of the flexion creases. In the meantime, it seems reasonable to assume that the flexion creases develop under genetic influences, in close morphologic relationship to the fetal volar pads . Early genetic and environmental factors causing hand malformations and alterations of the form or function of the hand, and occurring prior to the fetal crease development, may affect the developing flexion creases. The close correspondence between the appearance of the flexion creases and hand and digital movement (which, in turn, is associated with joint formation and muscular function) suggests that the same earlier factors are responsible for both crease development and flexion movement."
• 1991 Palmar, plantar, and digital flexion creases: morphologic and clinical considerations.
  - "Clearly, flexion creases have a significance of their own rather than only as appendices of the dermatoglyphic analysis and should, therefore, be approached appropriately. In some instances, they may be of more interest than the dermatoglyphics. Our understanding of the creases and their value is, however, as yet incomplete and the gaps in our insight limit the possible interpretations and practical applications of the knowledge gained from studies of various aspects of the flexion creases."
• 1988 Development of human palmar and digital flexion creases.
  - "Digital creases are well defined by 10 weeks; palmar creases are consistently seen by 13 weeks of gestation. The volar pads are present from 8 to 14 fetal weeks. A hand malformation or specific insult that occurs before the time of crease development and that alters the form or function of the fetal hand can cause secondary alterations increase patterns of the hand."
• 1986 Embryological development of human palmar, plantar, and digital flexion creases.
  - "We found that most creases develop concurrently with the appearance of the fetal volar pads and the rest develop independently of them. Furthermore, with some exceptions, the creases seem to develop independently of the flexion movements of hand and foot."
• 1983 Changes in the Sydney line during the first year of life.
  - "Of ninety-seven healthy newborns the Sydney line was no longer present at follow-up in 58.8 per cent of these infants."
• 1983 On the variability of "flexion creases" in the distal plantar areas of newborns.
• 1979 The genetics of palmar creases. A study in the inheritance of liability estimated from the incidence among relatives.
  - There is an increased frequency of abnormal creases in each of the groups of "at risk" newborns.
• 1977 Palmar creases in population studies.
  - "The significant frequency variation of palmar creases among different Indian populations and the bisexual and bimanual differences in the frequencies of different crease types indicate a regular distribution trend of the trait."
• 1977 Palmar creases and diseases: cancer and tuberculosis. - "The palmar flexion creases of cancer and tuberculosis patients are significantly different from those of the control population".
• 1973 Unusual palm creases and unusual children. The Sydney line and "type C" palmar lines and their clinical significance in a child development clinic - no abstract.

Other articles of interest (see also a compilation of articles from as early as 1925 by Martijn van Mensvoort.)

• 2004 Relative finger lengths predict men's behavior and attractiveness during social interactions with women - James R. Rooney and Dario Maestripieri - links to full article.
• 2002 Relative lengths of fingers and toes in human males and females.
• 2000 Asymmetry of signs of finger dermatoglyphics, physical potential and physical qualities of a man - Abramova TF, Nikitina TM, Izaak SI, Kochetkova NI. 
• 1997 Kabuki make-up (Niikawa-Kuroki) syndrome: cognitive abilities and autistic features.

John T. Manning - musical aptitude, verbal fluency, sports aptitude

Review of Manning's book: Digit Ratio: A Pointer to Fertility, Behavior and Health 

"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)".

• See also The First International Behavioral and Medical Biometrics Conference