A lobster fisherman from Maine in the US has told a BBC documentary on human instincts of the extraordinary lengths he went to in order to preserve his own life:   Doug Goodale cut off his own arm at the elbow in order to survive an accident at sea.

    He had become caught in a winch hauling lobster pots up from the sea floor, and could not free himself.

    The power of the winch left him hanging over the side of the boat, unable to either free himself or clamber back aboard.

    ‘I did it for my children’

    As the boat was rocked by stormy weather, he believes it was only a last, desperate
instinct for self-preservation that kicked in to save him.

    He said: “Nobody near you, no help, no radio, nobody to turn the radio off – that’s
it – you’re going to die.

    Somehow he managed to haul himself back onto the deck, dislocating his shoulder
in the process.

    His motivation was the image of his daughters appearing to him.

    “I don’t know how to explain it to people, but I swear, climbing onto the boat were
my two girls.”

    However, he was still trapped in the winch, bleeding heavily, and with no way of getting free, his only option was to pick up a knife and cut through his right arm.

    He then managed to pilot his boat back into harbour to get medical help.

    He said: “When my six-year-old tells me: ‘It doesn’t matter that you’ve only got one arm – you’re here’.

    “Now if you heard that from your kids, wouldn’t you take a knife and do the
same?”

    Survival
instincts are the theme of the first in a series of BBC documentaries starring
Professor Robert Winston.

    These
are abilities and reactions which are imprinted in us by millions of years
of evolution.

    Even
babies have the instinctive ability to spit out bitter-tasting food – which
may save them from eating poisonous food.

    And modern
phobias, say scientists, are simply left-overs from times when spiders
and snakes represented a genuine threat to life.

    From
the first years of life, humans develop a finely-tuned sense of “disgust”
which can protect them from items which might spread disease.

    And the
classic “fight or flight” response still works, with the first indication
of a threat launching swift brain activity to flood the body with adrenaline,
readying it for action.

    Human
instincts have been honed over 4.5 million years, and account for the natural
human preference for sweet or fatty foods.

    This
harks back, say experts, to millennia in which such food was scarce – humans
who craved it tended to thrive better than those who did not.

    It is
only in the past 100 years that food has become plentiful in any part of
the world.

    Human
Instinct will be broadcast on BBC One at 2100BST on Wednesday 23 October.