Data collection took place 6 hours a day, 5 days per week, during 4 months, resulting in a total of 510 hours of observation. Lateralized behaviour was assessed by means of behavioural sampling with continuous recording.

The limb/side of the body used by the monkeys when performing 13 spontaneous motor patterns, as well as the posture adopted at that moment, were recorded.

• List of the assessed motor patterns: self-grom, hold, pull, eat, smell, urine-wash, urine-smell, leading limb, side of leaning, side of suckling, side of carrying infant, tail wrap and tail-wrap mother.
• List of the assessed postures: sit, hang and cling,  lay, stand (tripedal) and stand on hind limbs (bipedal).