Background: Cage-free egg production methods are advancing in the European Union due to stringent housing regulations, animal welfare and consumer pressure. A changing production environment requests novel adaptation strategies of which the development of specific layer hybrids or strains is notably promising. Cage-free housing systems allow for a rather complete expression of social behaviour in laying hen populations; however, increasing stress, aggression and feather pecking are considered as major consequences. Objectives: This study aimed to detect a recently described SORCS2 polymorphism in newly developed Hungarian laying hen populations and observe potential associations with behavioural traits. Cage-free housing technologies with or without outdoor acces were also compared. Materials and Methods: Occurrence of behavioural traits were individually recorded for 119 hens. A novel PCR-RFLP method was developed and applied for SORCS2 genotyping with Rsal endonuclase. Results and Discussion: The SORCS2 polymorphism was present In the Hungarian populations, Callele frequencies varied between 75.1-85.5%. Homozygous TT genotype was the least prevalent across the three experimental populations with frequencies 2.2-4.2%. The experimental hybrid populations demonstrated different (p < 0.05) levels of aggression and activity related behavioural patterns. Homozygous CC animals showed more cases of aggressive behaviour compared to other genotypes. Feather pecking was more common In populations with outdoor access compared to the closed barn system (p < 0.05). The social behaviour of laying hens Is affected by many factors in an Immensely complex system. Selection efficiency on behaviour can be improved with a more profound knowledge on Its genetics.