From Human Behavior to Data (and Back)


Generalized linear models (GLMs) are widely used in the “big data” revolution. They are based on linear regression but have proven to be quite adaptable and robust to changes in variable distribution. Importantly, they allow us to make predictions on how a variable of interest changes when causative variables are manipulated.

For several decades scientists from different fields have realized that many features of the natural and human world do not follow Gaussian distributions, ie, they don’t cluster neatly around a mean. On the contrary, quantities such as the magnitude of Earthquakes, the income of individuals, the number of facebook friends or the word frequency have “heavy tail” distributions. That means that while there are many instances of weak Earthquakes and many poor people, from time to time there are a few extremely devastating Earthquakes and billionaires. It is unclear how informative GLMs are for these phenomena. GLMs are very useful to understand the mean or median behavior of a distribution, but they tell us little or nothing about the tails.

We want to tackle this problem by understanding which human-based activities have heavy tails; assess the impact of these rare events; and modify existing empirical models to give us information about them.

January 2019 – Ongoing

TEAM | Lília Perfeito

Scientific knowledge has been accepted as the main driver of development, allowing for longer, healthier, and more comfortable lives. Still, public support to scientific research is wavering, with large numbers of people being uninterested or even hostile towards science. This is having serious social consequences, from the anti-vaccination community to the recent “post-truth” movement. Such lack of trust and appreciation for science was first justified as lack of knowledge, leading to the “Deficit Model”. As an increase in scientific information did not necessarily lead to a greater appreciation, this model was largely rejected, giving rise to “Public Engagement Models”. These try to offer more nuanced, two-way, communication pipelines between experts and the general public, strongly respecting non-expert knowledge, possibly even leading to an undervaluing of science. Therefore, we still lack an encompassing theory that can explain public understanding of science, allowing for more targeted and informed approaches.

We are using a large dataset from the Science and Technology Eurobarometer surveys, over 25 years in 34 countries, to try to better understand what influences people’s attitudes towards science.

2016 – Ongoing

FUNDING | Welcome DFRH WIIA 60 2011, funded by the FCT and the Marie Curie Actions

TEAM | Frederico Francisco, Joana Gonçalves-Sá


Understanding how the public behaves during a health crisis is very valuable information for public health institutions. We found that during a health crisis setting, the 2009 flu pandemic, certain search trends proxied the population’s anxiety levels and that these were more associated with media reports. We are now expanding these techniques to better understand anxiety and fear spreading.

2017 – Ongoing

FUNDING | Fundação para a Ciência e Tecnologia

TEAM | Cláudio Vieira


Vieira, C. Online behavioral patterns in a health crisis setting, MSc thesis

Human reproduction does not happen uniformly throughout the year and what drives human sexual cycles is a long-standing question. We found that interest in sex peaks sharply online during major cultural and religious celebrations, regardless of hemisphere location. This online interest, when shifted by nine months, corresponds to documented human births, even after adjusting for numerous factors such as language and amount of free time due to holidays.

We further showed that mood, measured independently on Twitter, contains distinct collective emotions associated with those cultural celebrations. Our results provided converging evidence that the cyclic sexual and reproductive behavior of human populations is mostly driven by  culture and that this interest in sex is associated with specific emotions, characteristic of major cultural and religious celebrations.

2012 – 2016

FUNDING | PTDC IVC ESCT 5337 2012, Fundação para a Ciência e a Tecnologia (FCT); Welcome DFRH WIIA 60 2011,  FCT and the Marie Curie Actions

TEAM | Pedro Varela (former GM)

COLLABORATIONS | Luis Rocha, Ian Wood and Johan Bollen, Indiana University