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Computers harnessing digital footprints are
better judges of personality than friends and
family
New research shows that by analysing Facebook Likes, computer algorithms can
identify major personality traits of an individual more accurately than that
person’s friends, colleagues and closest family. Researchers have calculated the
average number of Likes a computer model needs to know you better than your
partner or parents - in some cases, even yourself.
University of Cambridge researchers have found that computers can achieve a more accurate
knowledge of your personality traits than your friends and colleagues. In fact, through a new
algorithm, artificial intelligence can draw inferences about you as quickly—and as accurately--
as your spouse can.
The study, published today in the journal PNAS, compares the ability of computers and people to
make accurate predictions about our personalities, with the computer looking at data and the
person using his or her own familiarity with us.
The researchers measured personality traits of 86,220 subjects in the areas of: openness,
conscientiousness, extraversion, agreeableness, and neuroticism. The idea was to see how
closely a computer could match the subject’s self-assessment in these areas, which would equate
to “understanding” his or her personality. To learn about the subject’s personality, the computer
looked at which articles, videos, artists, etc. the person had “liked” on Facebook. The
computer’s human counterparts were given questionnaires on the subject’s personality, which
were likewise compared to the person’s self-assessment.
The results are that by mining a person’s Facebook likes and assigning personality traits to them,
a computer’s artificial intelligence was able to ascertain a person’s personality more accurately
than the people who know them, with only the person’s spouse rivalling the computer.

2. This is an emphatic and promising indication of the ability of a person’s dearly-held traits to be
discovered by an analysis of data, not requiring person-to-person interaction. It shows that
machines can get to know us better than we’d previously thought, a crucial step in interactions
between people and robots or computers.
A computer could more accurately predict the subject’s personality than a colleague by analysing
just 10 likes; more than a friend with 70, a family member with 150, and a spouse with 300.
This demonstrates that with more data to analyse, a computer can know us the way our closest
companions do. This represents opportunities for versions of the sorts of human-computer
interactions depicted in films such as Ex Machina and the recent hit, Her, in which the
protagonist has a romantic relationship with a very emotionally-intelligent operating system.
Youyou Wu, lead author of the study, explains that the scenario depicted in Her has its workings
laid bare by the researchers’ findings:
“Our research,” Wu says, “provides empirical evidence that such a scenario is becoming
increasingly likely as tools for digital assessment come to maturity. The ability to accurately
assess psychological traits and states, using digital footprints of behaviour, occupies an important
milestone on the path towards more social human-computer interactions.”
Why is it important that a computer judge our personalities? Study co-author Dr. Michal
Kosinski, states, “The ability to judge a personality is an essential component of social living—
from day-to-day decisions to long-term plans such as whom to marry, trust, hire, or elect as
president.”
The results of an analysis of data pertaining to a person, can, then, be very useful in aiding
people in making decisions.
Wu explains that with this kind of data analysis, “Recruiters could better match candidates with
jobs based on their personality; products and services could adjust their behaviour to best match
their users’ characters and changing moods.” She adds that people may choose to augment their
own intuitions and judgments with data “when making important life decisions, such as choosing
activities, career paths, or even romantic partners.” Wu concludes, “It is possible that such data-
driven decisions will improve people’s lives.”
This may remind a person of the kind of data mining—and the attendant inferences—done by
Facebook, google, et al, today. A future with our habits being an open book may seem dystopian
to those who worry about privacy. The research team shares this concern, stating, “We hope that
consumers, technology developers, and policy-makers will tackle those challenges by supporting
privacy-protecting laws and technologies, and giving the users full control over their digital
footprints.”
As is the case with any technological breakthrough that involves some paradigm shift, the ethical
questions will be addressed on an ongoing basis.

3. Some may also question how a machine might serve as a true companion to the elderly or serve
as an employee in a way that is indistinguishable from a person. Time will tell, but the results of
this study show, for example, a machine detecting openness in a person, a trait that is not always
on display to a human. The study says people exhibiting openness may have Facebook Likes for
meditation or the art of Salvador Dali. These kinds of connections are a key component of the
kind of social thinking that would enhance a machine’s abilities to function alongside people.
The authors concede that the detection of some traits are best left to human abilities--those
without digital footprints and those depending on subtle cognition. But machines have a couple
of key advantages over humans in this area: the ability to retain and access large quantities of
information, and the ability to analyse these with algorithms. This provides the accuracy that the
human mind has a hard time achieving due to a human tendency to give too much weight to one
or two examples or to lapse into non-rational ways of thinking.
Artificial intelligence remains in its infancy, and the sophistication with which machines will be
able to use the data they collect figures to escalate in the coming years. Basic mirroring
techniques allow a robot to react to a person’s sadness or joy, while simulating some of the
“subtle cognition” mentioned above is a work in progress.
While debate rages about possible dangers of artificial intelligence run amok, the positive
applications of artificial intelligence growing a social intelligence are too numerous to ignore.
Further details on methodology
The study involved 86,220 volunteers on Facebook who completed a 100-item personality
questionnaire through the ‘myPersonality’ app, as well as providing access to their Likes.
Friends and family then described the subject’s personality via a 10-item version of the test the
user completed. The user then got an anonymous average. Research obtained a sample of
17,622 participants characterized by one Facebook friend, and 14,410 evaluated by two.
The researchers were able to corroborate the data with meta-analyses of previous studies on the
evaluations of acquaintance’s personalities.