Humor has a positive influence on learning in adults and school-aged children (1), yet few studies investigated the effect of humor on learning in infants. Our team was the first to show an influence of humor on social learning in infants as young as 18 months in a tool use context (2). In this earlier study, 64 infants had to use a rake to retrieve an out-of-reach toy after a demonstration of its use by an experimenter. The demonstration was done either in a humorous or in a neutral way. Our team found that 94% of the infants who laughed when exposed to a humorous demonstration then reproduced the target action compared to only 20% of infants who did not laugh or were exposed to the neutral demonstration. These results may be driven by different factors such as positive emotions, a surprise effect or the intensity of the emotions as measured by physiological parameters. The first aim of the current study was to understand the physiological/emotional mechanisms involved in the link between humour and learning by using a mutlidimensional approach. The second aim was to assess the generalizability of the previous findings on a larger age group (120 infants), aged between 14 and 22 months. In addition to the behavioral analysis, we measured several variables: both cardiovascular data by means of a wristband (to measure the intensity of emotions in a non invasive way); an automatic facial expression analysis; and a temperament measure by means of the ECBQ questionnaire, in order to investigate inter-individual differences in infants’ reactions to a humorous demonstration (3). Through this study, we investigated (a) the potential relationship between emotional intensity and learning in a humorous context, (b) whether infants under 18 months of age can learn better with humor, and (c) at what age infants consider our humorous demonstration to be funny. Our preliminary analyses of the physiological data seem to show no differences in infants’ heart rates both between (1) the neutral and the humorous demonstrations, and (2) between laughing, smiling and neutral infants. Therefore, we found no effect of the intensity of emotions on learning (see figure 1). Infants seemed to learn better when they were exposed to a humorous demonstration, as shown on figure 2. Furthermore, infants who smiled or laughed during the demonstration imitated more than non-laughing infants exposed to a neutral or humorous demonstration (see figure 3). The perception of the specific type of humor used in our study (measured by the laughing reaction) develops around 17 months of age. Surprisingly, our temperament questionnaire analysis suggested that laughing infants had more difficulty than others in regulating their negative emotions (figure 4). Further analysis of the cardiac signal are ongoing, to focus on the shape of the cardiac waves, correlated with facial expression analysis. These additional analysis seek to evaluate the effect of other positive emotions such as joy and surprise, both known to have a positive influence on learning in adults (4; 5).