Note: Where available, the PDF/Word icon below is provided to view the complete and fully formatted document
Disclaimer: The Parliamentary Library does not warrant or accept liability for the accuracy or usefulness of the transcripts. These are copied directly from the broadcaster's website.
Follow The Leader -

View in ParlViewView other Segments

NARRATION Why do so many of the world's species run with the pack? Following the flock can offer
many advantages - safety in numbers, the sharing of information on food resources and shelter,
co-operation on catching prey. But have you ever considered how large numbers of animals make a
collective snap decision?

Dr Ashley Ward

One of the reasons why collective decision making is so fascinating to us as researchers is that
these animals have the ability to make these decisions in the first place. After all they can't
vote, they can't discuss these decisions, yet they still manage to make incredibly efficient
decisions.

NARRATION

Dr Ashley Ward is finding out just how effective following the crowd can be. He's been testing the
decision making powers of these tiny little mosquito fish. To keep track of who's who, Ashley marks
up the fish with a non-toxic dye, after giving them a light anaesthetic. Each one now has an
individual colour marking. This Y shaped maze has been designed to sort out the idiots from the
experts.

Dr Ashley Ward

So what we've got here, Ruben, is a really simple experiment where we look at the way fish in
different group sizes make a really simple but important decision.

Ruben Meerman

In this channel is a nasty looking plastic predator fish and this channel is nice and clear so a
smart fish would go this way.

Dr Ashley Ward

And we predict that although this fish may have a decent chance at making the right decision, it
won't be quite as good as a group. OK so let's see how we go.

NARRATION

When the fish reaches the fork at the end of the channel, it literally takes a moment to decide
which way to go.

Ruben Meerman

Not that smart - you're gonna die buddy!

NARRATION

It's surprising how many of them get it wrong.

Dr Ashley Ward

We find that individuals are pretty poor at making these decisions, in fact about six out of 10
make the correct decision. Some of the fish will consistently make random or poor choices, whereas
some of the individuals, which we term experts, are consistently good at decision making.

NARRATION

But watch what happens when you let the masses decide! Once there's eight or more fish together,
over 80 per cent get it right! Not only are the fish more accurate, they also make a quicker
decision... So why does the crowd seem smarter than its members?

Dr Ashley Ward

What we think is that a certain proportion of these experts in a group is sufficient to guide the
entire group to make excellent decisions. So effectively the idiots can rely on the experts to make
good decisions.

NARRATION

Researchers are now tracking exactly where those experts sit in the group and how they might be
influencing the crowd.

Dr Ashley Ward

What we've ultimately found is that although one leader found it very difficult to lead a group,
two leaders could lead groups into doing almost anything. And part of the reason for that is what
we call the quorum rule, which is where animals in groups won't respond and copy a single
individual doing something, but they will respond if they see a threshold number of individuals, a
quorum of individuals doing something. It filters out bad decisions.

NARRATION

It's all about safety in numbers. If you're a fish, one of the most dangerous areas to live is a
coral reef. It's a highly predated environment, so making good decisions is crucial.

Ruben Meerman

These tropical damsel fish like their hidey holes and they won't make any risky decisions without
the backing of their mates.

NARRATION

These five fish have been given 'skid row reef' as a home - there's nowhere to hide and it's not a
safe place to hang out.

Dr Ashley Ward

The next step is then to add a larger piece of coral and they see this of course as it comes in and
that represents a far more attractive piece of habitat for them. So they've got to run the gauntlet
of crossing an open bit of space... No one individual wants to take the risk on its own.

NARRATION

Watch how the fish attempt the crossing. A couple of individuals try to make a move but without the
support of their group, decide to turn back. Finally the group crosses - but one little fella's
left behind!

Dr Ashley Ward

The very strange thing is, every time that's happeneded so far, even though it's usually been a
small individual or a subordinate individual, a couple of individuals will go back and collect it
and take it back across. It's an inexplicable but fascinating piece of behaviour.

NARRATION

But what can it teach us?

Dr Ashley Ward

We are using fish as our model organisms but realistically the results that we find should apply
equally to smaller animals like insects and larger animals like mammals, birds and even including
humans as well. So there are some people now in Germany who are working on collective behavior
models of how people escape from buildings that are on fire for instance because that is another
example of a collective behavior they use to parameterise their models on some of the information
that we gather on fish for example. What our research has shown, to our surprise, is that groups
are actually capable of making fast and accurate decisions. So they win on all counts.

NARRATION

Maybe next time instead of thinking for myself, I'll just follow the crowd...

Topics: Nature

Reporter: Ruben Meerman

Producer: Anja Taylor

Researcher: Anja Taylor

Camera: Peter Sinclair

Sound: Grant Roberts

Editor: Rowan Grant

Story Contacts

Dr Ashley Ward

Sydney University

Related Info

Dr Ashley Ward - School of Biological Sciences

Research on human crowd behaviour mirroring fish

^ top

YOUR COMMENTS

>> Add a Comment

Paul Nielsen - 08 Apr 2010 10:22:54pm

I think this research is most interesting. I have thought that the mob mentality operates at a
lower level then the individual particularly when considering football hooligans or racial riot
type events. Further for some time I have been thinking that the way we elect our leaders operates
from the lowest common denominator, typically the hip pocket. Of course characters like Pauline
Hanson took us back to the mob in a different way. How should I look at these thoughts now?

Thinking about our democratic process, we elect our leaders anonymously so there is no follow the
leader mob approach. Perhaps we should have an electronic system where we can see on the screen the
current voting trend and then we can decide to follow or go against the trend. This might produce
more useful results. Of course why waste the effort. What we should really do is identify the
smarties and let them make the decisions on behalf of the dummies. Smart Pollies can keep their
jobs. There could be an argument for non-compulsory voting here. Of course who are the smarties?
Who decides? The Scientists decide of course. Congratulations on some great research.

>> Reply