42 | New Scientist | 29 February 2020
commonly seen in children under 10.
Little wonder that search-and-rescue
veterans tell of lost people walking trance-like
past search parties, or running off and having to
be chased down and tackled. That is a problem
not only for those doing the searching, but
also for researchers attempting to understand
what goes through people’s minds when they
are lost. Cornell has found it is difficult to
interview someone right after they have been
found because “they are basically scrambled”,
with little recollection of what happened.
“You’ll never be able to figure out why lost
people make their decisions,” says Richard
Tomin, who worked for three decades as a
search-and-rescue coordinator for the states
of Vermont and Massachusetts.Finding patterns
What science can do is identify predictable
behaviours that could help rescuers narrow
their search areas. You can usually take it for
granted that your quarry has freaked out and
ventured further into the unknown. What you
really want to know is what they may have
done next. To answer this, researchers have
turned to the best data they can find: records
from tens of thousands of searches in the US,
Canada, Australia and the UK. They have
focused on aspects of behaviour that are easy
to measure, such as how far and for how long
someone travels before being rescued, the
degree to which they stray from their intended
course, the type of place they end up and,
crucially, whether or not they survive.
The records suggest that certain tendencies
are universal, intuitive to all humans in
unfamiliar landscapes. We are all drawn to
boundaries, such as the edge of a field, a forest
margin, a drainage ditch, a line of pylons or the
shore of a lake. Overall, most lost people who
are found alive end up in a building or on what
rescuers call a travel aid: a road, track or path,
say, or an animal trail. Rescuers now know
to always scout out such features first. It is a
strategy of probabilities: once you have ruled
out the most likely places, the chances increase
of finding someone elsewhere.
But real cases also reveal that many
predictable tendencies vary according to
a person’s age and gender, their mental state
and what they were doing when they got lost.
Children are less likely than adults to keep
moving, for instance, which explains why
96 per cent of them are found alive compared
with 73 per cent of adults. Children with
autism, meanwhile, usually take refuge
in some kind of structure, whether it is anHANS NELEMAN/GETTY IMAGESUnderstanding the
way lost people
behave can help
rescue teams
narrow their
search areasoutbuilding, a shed or even a thick bush.
People with dementia tend to head in a
straightline through whatever lies in their
way. And solo male hikers, once lost, travel
much further than any other category of
missing person. They just keep on walking
until someone finds them.
In other words, different types of people
get lost in different ways. This insight can
make a big difference to a search coordinator,
provided they have enough information about
the person they are looking for. Taking into
consideration the specifics of the person and
the terrain, it is possible to estimate the area
in which they are likely to be found or the
route they may have taken, and then adjust
that estimate as a search progresses. “The idea
is to get inside their head and predict how“ When people
with dementia
get lost, they
tend to head in
a straight line”