A new study finds IQ scores have been steadily falling for the past few decades and environmental factors, rather than genes are to blame, CNN reports.
The report says researchers analyzed the IQ scores of Norwegian men born across three decades and found that scores increased by almost 3 percentage points each decade for those born between 1962 to 1975. Those born after 1975, however, scored steadily worse.
The downward trend is supported by the findings of similar studies throughout Europe, the report says. The study's co-author, Ole Rogeberg, told CNN he believes environmental changes in education, media consumption, technological use and education are to blame.
In the past, researchers usually pinned genes as the likely culprit in variations in intelligence. The report notes the Norwegian study analyzed family members born into different environments in order to debunk that claim.
To that end, the study concludes that an IQ score may say more about the era in which a person lives rather than his or her genetic makeup.
Read CNN's full report.