Complete the summary below. Choose ONE WORD ONLY from the passage for each answer.

Oxytocin research

The earliest findings about oxytocin and bonding came from research involving [8]. It was also discovered that humans produce oxytocin during [9]. An experiment in 2005, in which participants were given either oxytocin or a [10], reinforced the belief that the hormone had a positive effect.

However, later research suggests that this is not always the case. A study at the University of Haifa where participants took part in a [11] revealed the negative emotions which oxytocin can trigger. A study at the University of Antwerp showed people’s lack of willingness to help [12] while under the influence of oxytocin. Meanwhile, research at the University of Amsterdam revealed that people who have been given oxytocin consider [13] that are familiar to them in their own country to have more positive associations than those from other cultures.