Children know the difference between right and wrong before they reach the age of two, according to new research _________ recently.

Scientists have _________ that babies aged between 19 and 21 months understand fairness and can _________ it in different situations. They say it is the first time that having a _________ of fairness has been identified in children at such a young _________.

Researchers say babies will watch a _________ for longer if they think it contains something unfair, so in two experiments the babies were _________ on how long they watched a live scenario (情景) about fairness.

In the first, 19-month-olds _________ two giraffe puppets (玩偶) given either a toy each or both toys to one of the giraffes. Longer looking times _________ that something was unusual or __________ to the baby. In this experiment, three-quarters of the babies looked longer when one giraffe got __________ toys.

In a second experiment, two women __________ each other with a pile of small __________ between them and an empty plastic box in front of each of them. In one scenario, one woman __________ put the toys away, while the other kept playing, but both women were given __________. In another scenario, both women put the toys away and both got a reward. The __________ 21-month-old babies looked reliably __________ when the worker and the slacker (偷懒的人) were rewarded equally.

Psychologist Stephanie Sloane, who led the study at Illinois University, said: “We discovered that 19 and 21-month-old babies have a general __________ of fairness, and they can apply it __________ to different situations.”

The __________ appear in Psychological Science, a journal published by the Association for Psychological Science.

Marmoset monkeys exist on a branch of the evolutionary tree that is distinct from the one that led to humans. But they constantly _______ researchers with social behavior that seems pretty highly evolved. Their social organization and _______ practices could have been the model for the phrase “It takes a village.” A dominant male and female breed, and their babies are carefully looked after by _______ family members who then aren’t free to breed themselves.

A new study further _______ the marmoset’s reputation for admirable community values. Researchers report that these caregivers share their food more generously with little ones _______ than when they’re surrounded by the watchful eyes of other community members. In complex societies where individuals band together for mutual protection, researchers have come up with a few widely accepted explanations for _______ behavior. But specific acts, like sharing a delicious cricket (蟋蟀) with a begging baby marmoset, seem to need more specific explanation.

One possibility is that an individual practices _______ as a means of enhancing his status among peers. By presenting that he is so well gifted with material goods that he can give some away, this do-gooder enhances his power within the group. That, in turn, may _______ prospective mates.

The other explanation for charitable behavior _______ that kindnesses extended to others are simply the fees of group membership, which offers some future promise of a chance to mate.__________ to share would result in exclusion from the group and a loss of potential partners.   

Scientists call this the “pay to stay” model. Importantly, for both of these models to work, acts of kindness must have a(n) __________. That suggests you would see more sharing in group settings; away from judging eyes, a caregiver might be more likely to keep food for himself or herself. And yet, in 2,581 tests conducted with 31 adult and 14 baby marmosets, the __________ appeared to be true.

Anthropologists (人类学家) from the University of Zurich carefully documented how often, in groups and in conditions that found caregiver and baby separated from the crowd, an adult would share his or her cricket. When alone with a baby __________ for a taste, adult marmosets shared their cricket 85% of the time. When in a group, caregivers offered up their cricket 67% of the time.” Our results show that helping in common marmosets is not driven by__________management or punishment avoidance, “the study authors reported. Rather, it is driven by a deep-down ____________ to help that is more strongly expressed when individuals are alone with young.”

Personality is one of the most interesting ways in which people are different from one another. But where does our personality come from? Are we ________ with it or does it change as we get older? A great deal of research into personality indicates that people’s personalities are more or less ________ before they are born. However, not everyone is ________. Psychologist Sanjay Srivastava and a team of researchers from the University of California, Berkeley, have just completed a large-scale study into personality. The researchers evaluated data from 132, 515 adults aged between 21 and 60. The team focused on five personality traits—what scientists call “The Big Five”. These are:

1. Conscientiousness—how careful, thorough and self-disciplined are you?

2.________ —how considerate and helpful are you?

3. Neuroticism—how self-conscious and tense are you?

4. Openness—how ________ , imaginative and open to new experiences are you?

5. Extraversion—how sociable and energetic are you?

What they found contradicted long-held assumptions about ________ personalities are set. Conscientiousness, a trait marked by organization and discipline and linked to success at work and in relationships, was found to increase through the age ranges studied, with the most ________ occurring in a person’s twenties. Similarly, agreeableness, a trait associated with being warm, generous and helpful, contradicted the theory that personalities don’t change after the age of 30.________, people in the study showed the most change in agreeableness during their thirties and continued to improve through their sixties.

The changes in these two traits revealed in the study seem to ________ the experiences that people tend to have at certain stages of their lives. Common sense tells us that people become more responsible and conscientious as they ________ and become better at managing their jobs and relationships. Similarly, agreeableness changes most in people’s thirties when many of them are raising a family and take on the role of ________. Openness showed small ________ in both men and women over time, a change that indicates less interest in forming new relationships, and reflects the tendency we have as we get older to spend more time with a small group of well-known relatives and friends, and less time going out and meeting ________ people.

The personality traits were ________ consistent between men and women, except for neuroticism and extraversion, with young women scoring higher than young men in both. However, the difference in neuroticism is only apparent in youth and young adulthood, and the gap between men and women in both neuroticism and extraversion ________ as people age.