The joint team of researchers, all hailing from the US, the Netherlands and Portugal, used both Google Trends and Twitter to analyze online searches from nearly 130 countries that included populations devoted to both Christianity and Islam.
The Alphabet-owned site was used to zero in on word searches from 2004 to 2014, while Twitter was tapped for the years between 2010 and 2014, to look at sentiments expressed by users. To determine where the user's feelings stood, officials used the Affective Norms for English Words, a "normative emotional rating" to determine arousal, dominance and pleasure, according to the University of Florida's Center for the Study of Emotion and Attention.
"The rise of the web and social media provides the unprecedented power to analyze changes in people's collective mood and behavior on a massive scale," Luis Rocha, a researcher who co-led the study, said in a statement. "This study is the first 'planetary-level' look at human reproduction as it relates to people's moods and interest in sex online."
The analysis ultimately revealed to officials that interests in sex spiked during major cultural or religious celebrations based on the increased use of the word "sex" or similar sexual terms in web searches. Officials later indicated that the peak corresponded with an increase in births nine months after the holiday in countries that provided birth-rate data.
"We observe that Christmas and Eid-Al-Fitr are characterized by distinct collective moods that correlate with increased fertility," Rocha said. "Perhaps people feel a greater motivation to grow their families during holidays when the emphasis is on love and gift-giving to children."
"The Christmas season is also associated with stories about the baby Jesus and holy family, which may put people in a loving, happy, 'family mood,'" the researcher added.
Though previous studies suggested that an increase in sex is related to the changing of the seasons, researchers tossed out the notion that biological shifts caused by daylight, temperature and food availability played a role, since the study looked at countries across the world.
According to Rocha, the findings can help public health researchers pinpoint the best time of the year for launching public awareness campaigns to encourage safe sex.
The study was conducted by researchers from Indiana University, Wageningen University and the Instituto Gulbenkian de Ciência.
