How Stephen Hawking Got It Wrong: Cognitive Biases and A Quiet Place: Day One Lead to Unwarranted Fears of Messaging Extraterrestrial Intelligence (METI)

The late cosmologist Stephen Hawking said that if humankind receives a signal from extraterrestrials, we should stay quiet. "Meeting an advanced civilization could be like Native Americans encountering Columbus. That didn't turn out so well," he said in his 2016 documentary Stephen Hawking's Favorite Places. If we let the aliens know we're here, he argued, we might be inviting an interstellar armada that could wipe out life on Earth.

Hawking overlooked an essential point: it's too late to hide. For two billion years Earth's microbial life has been making itself known to the universe through changes to our planet's atmosphere. In the next twenty years, humankind will have space-based observatories capable of detecting extraterrestrial life by studying the chemical composition of atmospheres covering exoplanets. Advanced extraterrestrials will have even greater capacities.

Similarly, for the past century Earth has been leaking accidental radio and television signals into space, letting eavesdropping aliens know that we have rudimentary technology. Broadcasts of I Love Lucy have been our interstellar emissaries for decades.

We can evaluate the feared dangers of Messaging Extraterrestrial Intelligence (METI), such as the possibility of being discovered for the first time through our intentional messages. If we project our own advances in radio technology since the origins of radio astronomy in the 1930s, in 200 years humans will have the capacity to detect Earth's level of leakage radiation at a distance of 500 light-years - far beyond the range of METI's current targets. Any civilization capable of interstellar travel would already know we're here, so there is no added risk of METI. If there are any paranoid aliens out there, intent on eliminating the galactic competition, they've had plenty of time to come to Earth.

Even though we might logically understand that it's too late to hide, several common cognitive biases lead to a nagging fear that it's somehow riskier to transmit than to remain quiet, so we should refrain. For example, omission bias makes us assume it's safer to do nothing than to do something. The danger of giving into that fallacy is apparent through the inaction of individuals who chose not to be vaccinated against COVID, rather than to take action that benefitted the public health.

Additional cognitive biases - the availability heuristic and loss aversion - also affect risk assessment. For example, the availability heuristic shows how vivid, available images like those in the science fiction film A Quiet Place: Day One (release date June 28, 2024) can lead to fears of METI.