Stuttering is a communication disorder "whose primary symptoms are disfluencies, involuntary disruptions in the normal flow of speech" (Smith & Weber, 2017, p. 2485. People Who Stutter (PWS) exactly know what they would like to say but they encounter difficulties in producing a normal flow of speech (National Institutes of Health, 2020). Findings support that stuttering has a complex and heterogeneous etiology (Smith & Weber, 2017), ranging from genetic predisposition (Frigerio-Domingues & Drayna, 2017) to psychosocial factors (Boyle, 2016). Psychosocial factors are related to the tendency to react anxiously to novel situations or people (Mongia et al., 2019) or with the negative attitude of parents or listeners to speech, who focus especially on involuntary disfluencies or stress (Kefalianos et al., 2012).First symptoms of stuttering usually appear around 2 and 4 years of age (National Institute of Health, 2020), when the child begins to use connected language, longer linguistic forms, and more complex sentences (Wolk & LaSalle, 2015). Generally, in most cases a recovery occurs spontaneously after one year from the first symptoms (Blomgren, 2013). However, if the problem persists, the likelihood for stuttering increases, leading to several difficulties in social, academic, and workplace settings later on (Craig & Tran, 2006). Linked to the stuttering, signs of stress are manifested through facial ten-Clínica y Salud (2021) xx(x) xx-xx Funding: Jennifer E. Moreno-Jiménez was granted a predoctoral fellowship, FPI-UAM 2017 of the