It is widely agreed that human infants share certain innate core magnitude processing abilities with other species, i.e. infants are born with a non-verbal, non-symbolic understanding of quantities which is possible to investigate in early infancy using brain research methodologies. This innate ability, number sense, enables us to detect number differences between sets of objects. Although magnitude processing/number sense has been studied in human infants, its intergenerational transmission has not been studied.

Here we investigated early brain responses of newborns related to ability to detect changes in small numerosity in auditory sound stream and explored whether this early index of magnitude processing is associated with their parents’ basic mathematical skills. We measured EEG in newborns 2-3 weeks after their due date during auditory stimulation. The stimuli were 1-part, 2-part and 3-part sine tones. Their parents participated in skill assessment with basic arithmetic tasks, a non-symbolic mathematical skill using a magnitude comparison task, and related cognitive skills such as processing speed and rapid automatized naming tasks (RAN).

The results among the 100 parent-child dyads (57 father-child dyads and 43 mother-child dyads) showed that newborns’ brain responses (especially the responses to 1-part stimuli presented among the 2-part stimuli), correlated with parents’ basic arithmetic skills and quantity RAN (quantities 1-4 represented as dots similar to dice). The correlations were significant in both mother-child dyads and in father-child dyads. Additionally, the responses to 3-part stimuli presented among the 2-part stimuli correlated with the fluency in magnitude comparison and number comparison tasks. The results suggest that newborn brain responses varying in number of sine tones may reflect their magnitude processing ability, and that math skills seem to transfer in families via this innate ability.

Studies that show positive associations between speech input from parents and the language skills of young children prompt us to assume that differences in language abilities are directly caused by how and how much parents talk. However, parents’ input also reflects their language skills, which are subject to genetic influences that they pass on. Thus parents could affect the language skills of children through environmental and genetic pathways. Studies rarely correlate parent and child language skills, either because they do not consider that parent input might depend on their skills, or because they equate input with parents’ language skills. We argue that parent input and language skills are related but separate constructs, and that it is important to know the effect of both to understand the intergenerational transmission of language skills and the variation in children’s language abilities. As a first step in this direction, we present a systematic review on the similarity between the language skills of children and their parents, as well as between the father and mother themselves; the latter correlation informs our interpretation of the genetic influence of the two parents on their children. If two parents are more alike than we would expect by chance, we also expect a larger correlation between parents and children. We performed a pre-registered systematic search in PsycINFO, SCOPUS, Web of Science, ERIC and ProQuest Dissertations and Theses. We present correlations between the language skills of parents and their children and between the language skills of the two parents in their native language(s) using a language test or assessment. We document the magnitude of these associations, summarize the explanations these studies provide for them and identify potential moderators. Lastly, we assess the methodological quality of studies included in our review and document potential differences between high and low-quality papers.

Individual differences in literacy and numeracy – that is, how well one can read, write, and work with numbers – become apparent as early as when children start primary school and are crucial indicators of their later educational success. Twin and family studies indicate that children’s literacy and numeracy skills, as well as educational attainment (EA) in adulthood, are shaped through the complex interplay of genetic and environmental factors. Yet, less is known about the genetic etiology of literacy and numeracy. Additionally, there is a lack of evidence that pinpoints common and domain-specific genetic effects to literacy and numeracy as well as how such genetic effects might differ between childhood skills and adults’ EA.

Here, we predict children’s literacy and numeracy and adults’ EA from their inherited DNA differences, capitalizing on data from up to N = 4,429 twins participating in the Netherlands Twin Register. Literacy and numeracy were assessed via teacher and parental reports of children’s school achievement at age 12 years. Adult participants indicated their highest educational qualification as a measure of EA. The twins’ DNA differences in the form of polygenic scores for reading ability, dyslexia, and years of education were used to predict literacy, numeracy, and EA. Preliminary analyses showed that stronger genetic propensities for reading and years of education predicted higher literacy and numeracy in children (up to R2=5.1%) and higher adult EA (up to R2=6.4%). By contrast, the dyslexia polygenic score did not explain differences in child literacy and numeracy nor adult EA. Further, we will test how prediction accuracy changes when leveraging updated versions of these polygenic scores with increased statistical power. Findings will contribute to our understanding of the genetic intertwining between literacy, numeracy, and EA and inform about the potential of polygenic scores for use in education research.

Recently, general cognitive abilities (g) have been quantified in blood DNA-methylation samples of adults that can be applied as methylation profile scores in separate target samples (Epigenetic-g). Here, we evaluate whether Epigenetic-g in children, adolescents, and adults is associated with cognitive development, academic performance, and socioeconomic attainments. Our preregistered analyses include n = 1,830 8-18-year-olds from the US Texas Twin Project, n = 5,432 5-32-year-olds from the German Twin Family Panel Study (TwinLife), and n = 2,262 0‑72‑year‑olds from the German SOEP-Gene cohort. In the Texas Twin Project, which provided saliva DNA-methylation samples, Epigenetic-g is associated with levels of general cognitive ability, longitudinal gains in g, and math and reading school grades. For instance, no child with below average Epigenetic-g attended advanced math classes. In contrast, in German SOEP-Gene, which provided buccal DNA-methylation samples, quantifications of Epigenetic-g were not associated with cognitive performance, in line with previous reports of low blood-to-buccal cross-tissue correspondence. These results suggest that Epigenetic-g quantified in saliva samples, but not buccal tissue, is sensitive to individual differences in levels and developmental gains in g as well as real-world academic outcomes in children and adolescents. Similar to widely used measures of biological aging, DNA-methylation quantifications of psychological phenotypes may be useful tools to study the etiology of individual differences across the lifespan.