Disturbing video shows days-old baby monkeys tormented in experiments at the University of Washington; the six-year study, costing $4.2 million, involved 32 pregnant macaques and 28 separated infants; Peta calls for the closure of US primate research centres

• The video offers the first filmed look inside these experiments.
• It shows tiny monkeys shrieking in fear and gripping blankets, their only form of comfort, as researchers shave their heads, attach electrodes and test their reflexes and memory to determine whether exposure to a neurotoxin in the womb has damaged their