To investigate the effect of early cognitive experiences on personality later in life, adult (5 months old) individuals were exposed a novel arena test and a novel object test. These assays are classic personality tests used both in the fowl and for other vertebrates. These personality assays score variation in activity, exploration, fear and neophobia among individuals.  

An arena (4m²) made out of wood and mesh with a mesh roof and cardboard floor was used. The floor was covered with a 1.5 cm layer of peat. To avoid visual exploration of the whole arena from the starting position and thereby encourage exploration, familiar objects in form of two large food bells and one small water bell were placed in the arena (figure1).

An individual was placed solitary in the arena and was tested for ten minutes.  Behaviours were recorded every 10 seconds, using instantaneous scan sampling. Recorded behaviours were based on previous studies describing personality in the fowl and included ‘vigilance’ (i.e. proportion of time spent standing or walking alert, having the head high above shoulder-height), ‘activity’ (i.e. locomotion; proportion of time walking and running), ‘foraging’ (i.e. proportion of time spent with its head down close to the ground either pecking or searching for food). In addition, ‘latency to move’ (i.e. duration in seconds until the bird started moving after being introduced into the arena) was recorded. Lastly,  ‘number of escapes’ (i.e. number of  times a bird tried to escape from the arena by attempting to fly out) in case of occurrence was recorded. 

Directly after the novel arena test, a novel object was placed in the arena (figure 2). This was a grey stuffed animal measuring 15 cm and with approximately 2 cm large green and black eyes. Again, the individual was observed for ten minutes. The same behaviours as in the novel arena was recorded. The individual was later returned to its home pen. The arena was cleaned when needed, removing faeces and filling up peat.