Conducting studies to establish conclusions on ASD populations through BAP samples necessarily imply the existence of a measurement tool capable of measuring an updated BAP operationalization.

The BAP, as the autistic phenotype, has been proposed to share ASD internal structure, and, consequently, tests that aim to measure the BAP should be developed upon an updated two-factor internal structure. According to the Standards (2014), whether two tests have defined the same construct differently and, thus, contain different internal structures, those tests are assessing essentially two different things. In this regard, the reconciliation of BAP and ASD will drive certainly to restore any previous measurement process. As such, uncertain cases of those individuals who do not have a clear ASD diagnosis but have shown highly impaired BAP behaviors and, in lower intensity, independent and functional adults with some core autistic behaviors that impoverish their social interactions, as well as those capable of camouflaging or smoothing specific deficits (developing ways to cope with them Hull et al., 2017 Livingston et al., 2019 Mandy, 2019), could also benefit from well-established autism assessment protocols and interventions which will represent, indeed, a clinical milestone. On the other hand, accepting that both constructs essentially represent the same spectrum of traits to a different degree, could bring many advantages for several populations. Finally, we can as well take advantage of BAP samples to test assessment and intervention procedures before applying them to clinical and more sensible samples. In the same way, it will also increase the understanding of the developmental path of autism in elder adults (Stewart et al., 2018) which has not been very studied yet.

Likewise, it will also help to uncover autistic genetic mechanisms (Gaugler et al., 2014 Robinson et al., 2011) by exploring the presence of BAP in parents of children diagnosed with ASD. The reharmonization of the BAP and ASD constructs will highly contribute to the field as it will operationalize the BAP in the spectrum, increasing its understanding and, providing further information regarding how core autistic deficits are expressed differentially on each severity level. This has generated a discrepancy between ASD and BAP conceptualizations that, in our opinion, needs to be addressed. Even though the definition of ASD has been updated over time, the most popular BAP definition has barely changed and has not been revised according to the most recently updated definition of ASD (APA, 2013). As pointed out by numerous authors (e.g., Morrison et al., 2018 Wainer et al., 2011), BAP traits correspond directly to the primary characteristics of ASD: Social Communication and Social Relation Impairment (SCI) alongside a Pattern of Restricted Repetitive Behaviours and Interests (RRBs American Psychiatric Association, 2013). The broad autism phenotype (BAP) has been described as a set of subthreshold features qualitatively similar to those existing in autism spectrum disorder (ASD), which is continuously distributed and spreads beyond ASD family members into the general population (Constantino & Todd, 2003 Hoekstra et al., 2007 Hurst et al., 2007 Stewart & Austin, 2009).

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