Date Published: May 15, 2015
Publisher: Public Library of Science
Author(s): Shoko Tsuchimine, Junji Saruwatari, Ayako Kaneda, Norio Yasui-Furukori, Daimei Sasayama.
There is no scientific consensus that a relationship exists between the ABO blood group and personality traits. However, a recent study hypothesized that the dopamine beta-hydroxylase (DBH) gene is in linkage with the ABO gene. The sample population consisted of 1,427 healthy Japanese subjects who completed the Temperament and Character Inventory (TCI). Each subject’s ABO blood type was determined by genotyping the rs8176719 and rs8176746 ABO gene single-nucleotide polymorphisms (SNPs) using a TaqMan genotyping assay. The relationships between the six ABO genotypes or four ABO phenotypes and personality traits were examined using a multivariate analysis of covariance (MANCOVA), controlling for age and sex. The MANCOVA data showed a significant difference in TCI scores among the ABO genotype groups (F [7, 1393] = 3.354, p = 0.001). A subsequent univariate analysis showed a significant difference in the mean scores for Persistence among the genotype groups (F = 2.680, partial η2 = 0.010, p = 0.020). Similarly, dividing the ABO blood type into four phenotypes revealed a significant difference among the phenotype groups (F [7, 1397] = 2.529, p = 0.014). A subsequent univariate analysis showed a significant difference among the phenotype groups in the mean scores for Persistence (F = 2.952, partial η2= 0.006, p = 0.032). We observed a significant association between ABO blood group genotypes and personality traits in a large number of healthy Japanese subjects. However, these results should be regarded as preliminary and should be interpreted with caution because it is possible that the association between ABO blood group genotype and the Persistence trait is relatively weak.
Personality traits influence many aspects of normal and pathological behaviors [1–5]. Temperament traits, the most basic part of personality, have been correlated with neurotransmitter systems and are genetically controlled . In the last decade, a large number of studies have focused on the detection of genetic variants associated with specific temperament traits, and numerous findings have been reported . Although a consensus has not been reached, many genes show reproducible associations with personality traits, including the current consensus that personality is approximately 50% heritable .
Tables 1 and 2 show the genotype and phenotype distributions of the ABO group, as well as the mean scores and standard deviations for the seven TCI factors for each genotype and phenotype. The allele groups showed the following frequencies: A alleles (26.7%), B alleles (17.7%), and O alleles (55.6%). These ABO gene allele and phenotype frequencies were similar to those observed in other samples from Japanese populations . The genotype distribution was consistent with Hardy-Weinberg equilibrium (p = 0.46). A significant but small to moderate degree of linkage disequilibrium was detected between ABO rs81746746 and DBH rs1611115 (|D’| = 0.4009, p = 0.005819) and between ABO rs8176719 and DBH rs1611115 (|D’| = 0.2131, p = 0.006529), and a large linkage disequilibrium was observed between ABO rs8176749 and 8176719 (|D’| = 1, p = 7.71×10-66).
In this study, we investigated possible associations between ABO phenotype and genotype and personality traits based on Hobgood’s hypothesis . The results of this study showed significant differences in Persistence scores according to both genotype and phenotype. Subjects with the A allele had higher Persistence scores than subjects with B or O alleles in both case genotype and case phenotype. However, these results are inconsistent with those of previous studies [10–12].
Although associations between ABO blood type groups and personality traits have been treated as pseudoscience, we observed a significant association between ABO blood group genotype and personality traits in a large number of healthy Japanese subjects. However, these results should be regarded as preliminary and should be interpreted with caution because it is possible that the association between ABO blood group genotype and the Persistence trait is relatively weak. Further studies of this relationship between ABO blood type and personality traits could promote the understanding of human behavior and advance efforts to assess future risks of illness.