Frühes postnatales Testosteron ist ein Indikator für Sprachfertigkeiten

Eine interessante Studie zu Geschlechterunterschieden bei der Sprache:

Highlights

•There was a sex difference in salivary testosterone in infants aged 1–3 months.
•Testosterone in infancy predicted vocabulary in boys and in girls in toddlerhood.
•The sex difference in vocabulary was mediated by testosterone in infancy.
•Testosterone in infancy may contribute to early language development.

Abstract
During the first few years of life, girls typically have a larger expressive vocabulary than boys. This sex difference is important since a small vocabulary may predict subsequent language difficulties, which are more prevalent in boys than girls. The masculinizing effects of early androgen exposure on neurobehavioral development are well-documented in nonhuman mammals. The present study conducted the first test of whether early postnatal testosterone concentrations influence sex differences in expressive vocabulary in toddlers. It was found that testosterone measured in saliva samples collected at 1–3 months of age, i.e., during the period called mini-puberty, negatively predicted parent-report expressive vocabulary size at 18–30 months of age in boys and in girls. Testosterone concentrations during mini-puberty also accounted for additional variance in expressive vocabulary after other predictors such as sex, child’s age at vocabulary assessment, and paternal education, were taken into account. Furthermore, testosterone concentrations during mini-puberty mediated the sex difference in expressive vocabulary. These results suggest that testosterone during the early postnatal period contributes to early language development and neurobehavioral sexual differentiation in humans.

Wenig Testosteron in einer bestimmten Phase führt also zu besseren sprachlichen Fähigkeiten.

Das passt gut zu der sonstigen Forschung in dem Bereich:

Sprache und Testosteron

Leser Dummerjan hatte auf eine interessante Studie hingewiesen, nach der Testosteron den Spracherwerb verzögern kann. Leider habe ich den Volltext der Studie nicht gefunden, hier ist der Abstract:

Background:  Preliminary evidence suggests that prenatal testosterone exposure may be associated with language delay. However, no study has examined a large sample of children at multiple time-points.

Methods:  Umbilical cord blood samples were obtained at 861 births and analysed for bioavailable testosterone (BioT) concentrations. When participating offspring were 1, 2 and 3 years of age, parents of 767 children (males = 395; females = 372) completed the Infant Monitoring Questionnaire (IMQ), which measures Communication, Gross Motor, Fine Motor, Adaptive and Personal–Social development. Cut-off scores are available for each scale at each age to identify children with ‘clinically significant’ developmental delays. Chi-square analyses and generalized estimating equations examined longitudinal associations between sex-specific quartiles of BioT concentrations and the rate of developmental delay.

Results:  Significantly more males than females had language delay (Communication scale) at age 1, 2 and 3 years (p-values ≤. 01). Males were also more likely to be classified as delayed on the Fine-Motor (p = .04) and Personal–Social (p < .01) scales at age 3 years. Chi-square analyses found a significant difference between BioT quartiles in the rate of language delay (but not Fine-Motor and Personal–Social delay) for males (age 3) and females (age 1 and 3). Generalized estimating equations, incorporating a range of sociodemographic and obstetric variables, found that males in the highest BioT quartile were at increased risk for a clinically significant language delay during the first 3 years of life, with an odds ratio (OR) of 2.47 (95% CI: 1.12, 5.47). By contrast, increasing levels of BioT reduced the risk of language delay among females (Quartile 2: OR = 0.23, 95% CI: 0.09, 0.59; Quartile 4: 0.46, 95% CI: 0.21, 0.99).

Conclusion:  These data suggest that high prenatal testosterone levels are a risk factor for language delay in males, but may be a protective factor for females.

Zu den Unterschieden bei der Sprache von Mann und Frau hatte ich schon ein paar Artikel:

Diese Studie macht noch einmal deutlich, dass auch hier die Hormone eine Rolle spielen.

Aus einem Artikel zu der Studie:

The research team wanted to test whether this developmental delay could be due to prenatal exposure to sex steroids such as testosterone, as male fetuses are known to have ten times the circulating levels of testosterone compared to females. The team proposed that higher levels of exposure to prenatal testosterone might increase the likelihood of language development delays. Dr. Whitehouse’s team measured levels of testosterone in the umbilical cord blood of 767 newborns before examining their language ability at one, two, and three years of age. The results showed that boys with high levels of testosterone in cord blood were between two and three times more likely to experience language delay. However, the opposite effect was found in girls, where high levels of testosterone in cord blood were associated with a decreased risk of language delay. Dr. Whitehouse said the finding is significant in that it gives a biological explanation for why boys’ language development differs to that of girls.

Die Biologie der Sprache: Pidgin und Kreolsprachen

Das etwas hochkomplexes und kulturabhängiges wie die Sprache auf biologischen Grundlagen beruhen kann, zeigt sich an Pigdinsprachen und Kreolsprachen

Pidginsprachen sind Sprachen, die entstehen, wenn Leute keine gemeinsame Sprache sprechen und sich irgendwie verständigen müssen. Sie sind ein Mischmasch dieser Sprachen ohne eine vernünftige Grammatik oder Struktur. Diese kann man aber sehr einfach in eine solche Sprache einbringen: Man braucht nur ein paar Kinder, die diese als Muttersprache erlernen. Die Kinder entwickeln automatisch aus dem Pigdin eine „Muttersprache“, eben ein Kreol.

Steven Pinker führt dies in „The Language Instinct“ wie folgt aus:

When speakers of different languages have to communicate to carry out practical tasks but do not have the opportunity to learn one another’s languages, they develop a makeshift jargon called a pidgin. Pidgins are choppy strings of words borrowed from the language of the colonizers or plantation owners, highly variable in order and with little in the way of grammar. Sometimes a pidgin can become a lingua franca and gradually increase in complexity over decades, as in the „Pidgin English“ of the modern South Pacific. (Prince Philip was delighted to learn on a visit to New Guinea that he is referred to in that language as fella belong Mrs. Queen.) But the linguist Derek Bickerton has presented evidence that in many cases a pidgin can be transmuted into a full complex language in one fell swoop: all it takes is for a group of children to be exposed to the pidgin at the age when they acquire their mother tongue. That happened, Bickerton has argued, when children were isolated from their parents and were tended collectively by a worker who spoke to them in the pidgin. Not content to reproduce the fragmentary word strings, the children injected grammatical complexity where none existed before, resulting in a brand-new, richly expressive language. The language that results when children make a pidgin their native tongue is called a creole.

Das ist eine bemerkenswerte Fähigkeit des Gehirns, die nach der dort vertretenen Ansicht eben auf eine Universalgrammatik schließen läßt, die kulturell nur mit den entsprechenden Wörtern und bestimmten Ausgestaltungen der Regeln versehen wird.

Es spricht deutlich gegen einen „Blank Slate„, sondern für eine Vorformatierung des Gehirns. Wir werden nicht einfach durch Sprache gestaltet, sondern finden einiges bereits in unserem Gehirn vor, was dann durch Kultur ausgestaltet wird. Anzeichen dafür, dass wir eine gewisse Vorformatierung haben, ergeben sich meiner Meinung nach aus vielen Studien, gerade auch im Geschlechterbereich (zu Unterschieden in den Sprachfähigkeiten vgl. „Sprache und Unterschiede im Gehirn von Mann und Frau„).