The genes of the Major Histocompatibility Complex (MHC), which plays a fundamental role in the immune system, are some of the most diverse genes in vertebrates and have been connected to mate choice in several species, including humans. While studies suggest a positive relationship between MHC diversity and male facial attractiveness, the connection of MHC diversity to other visual traits and female attractiveness is still unclear. The purpose of this study was to investigate further whether MHC heterozygosity, indicating genetic quality, is associated with visual traits affecting mate preferences in humans. In total 74 Latvian men and 49 women were genotyped for several MHC loci and rated for facial and, in men, also body attractiveness. The results indicate a preference for MHC heterozygous female and male faces. However, the initially positive relationship between MHC heterozygosity and facial attractiveness becomes non-significant in females, when controlling for multiple testing, and in males, when age and fat content is taken into account, referring to the importance of adiposity in immune function and thus also attractiveness. Thus overall the effect of MHC heterozygosity on attractiveness seems weak. When considering separate loci, we show that the main gene related to facial attractiveness is the MHC class II DQB1; a gene important also in viral infections and autoimmune diseases. Indeed, in our study, heterozygous individuals are rated significantly more attractive than their homozygous counterparts, only in relation to gene DQB1. This study is the first to indicate a link between DQB1 and attractiveness in humans.

主要组织相容性复合体 (MHC) 的基因在免疫系统中发挥着重要作用，是脊椎动物中最多样化的基因之一，并且与包括人类在内的多个物种的配偶选择有关。虽然研究表明 MHC 多样性与男性面部吸引力之间存在正相关关系，但 MHC 多样性与其他视觉特征和女性吸引力之间的联系仍不清楚。本研究的目的是进一步调查表明遗传质量的 MHC 杂合性是否与影响人类择偶偏好的视觉特征相关。总共对 74 名拉脱维亚男性和 49 名女性进行了多个 MHC 基因座的基因分型，并对面部吸引力以及男性的身体吸引力进行了评估。结果表明对 MHC 杂合的女性和男性面孔的偏好。然而，在控制多重测试时，MHC 杂合性与面部吸引力之间最初的正相关在女性中变得不显着，而在男性中，当考虑到年龄和脂肪含量时，这指的是肥胖在免疫功能中的重要性，因此还有吸引力。因此，总体而言，MHC 杂合性对吸引力的影响似乎很弱。当考虑单独的基因座时，我们发现与面部吸引力相关的主要基因是 MHC II 类 DQB1；该基因在病毒感染和自身免疫性疾病中也很重要。事实上，在我们的研究中，杂合子个体被认为比纯合子个体更具吸引力，这仅与基因 DQB1 有关。这项研究首次表明 DQB1 与人类吸引力之间存在联系。