WASHINGTON (AP) – Should pre-school be more about ABCs or learning to play with others? With the help of Twiggle the Turtle, scientists found out that youngsters do better if they do both.

So concludes a major study in Head Start programmes in Pennsylvania, research with implications for pre-schools and parents everywhere.

Face it, four-year-olds are loveable but self-centred, impulsive and prone to meltdowns. Teaching them not to whack a classmate who snatches a toy is a big part of pre-school socialisation.

But growing awareness that early learning is important to future school achievement has put more pressure on pre-school's academic side, especially efforts to eliminate achievement gaps between low-income and wealthier students.

Both skills are intertwined, said Penn State University psychology professor Karen Bierman, who led the new study.

"If pre-schools focus just on the facts – let's just get the letter knowledge in, let's just get the number knowledge in – they're really missing the engine that's going to drive the desire and motivation for learning," she said.

To prove the relationship, Penn State researchers turned to Head Start, the federal pre-school programme for poor children.

With funding from the National Institutes of Health and other federal agencies, they divided 44 Head Start classrooms with about 350 four-year-olds. Half taught a traditional Head Start curriculum.

The other half added to their traditional teaching a programme called REDI Head Start that included weekly special social lessons – puppets or stories that teach specific problem-solving skills.

Take Twiggle the Turtle. He pushed his friend after she knocked over his block tower, and thus couldn't play anymore. A wise old turtle told Twiggle that when he got upset, he should go inside his shell, take a deep calming breath, and say what bothered him and how it makes him feel: "It really made me mad that you knocked my blocks over."

Cross your arms to be like Twiggle in his shell, the teachers tell their pres-choolers. Then practice what James might say if Suzie takes the toy he wants, or if Billy says something mean to Tommy.

Instead of the vague "use your words" advice that parents tend to spout, "be like Twiggle" became the theme and a good habit.

"What's really beautiful: You'll see children over in the blocks centre and someone stands up and does the turtle and talks, and someone else does the turtle and talks, and then they sit down and play again," Bierman said.

Another enrichment tested: More intense reading-readiness instruction. It included interactive reading – where the teacher asks questions after each page or so to work on vocabulary and comprehension – and listening games to tease out discrete sounds in words. Both require self-control to focus.

By year's end, pre-schoolers given enriched instruction scored higher on tests of school readiness, both social and academic, Bierman reported last week in the journal Child Development.

Some examples: Seventy percent of kids in the enriched classes showed little or no disruptive behaviour, compared to 56 percent in the regular classes. Twelve percent of the enriched students still struggled to focus attention on academic tasks, compared to 21 percent in regular classes. And 20 percent in enriched classes exceeded a national vocabulary norm compared with 15 percent in regular classes.

Pre-schools always aim to teach good behaviour, but a crowd-control approach – "stop doing that, put that down, don't pull his hair" – doesn't help children learn to resolve conflict, said James Griffin of the NIH's National Institute of Child Health and Human Development. The new study shows how to teach children positive steps, not just what to avoid, in a way that's easy for busy teachers, he said. Much of the enriched curriculum is commercially available, along with similar programmes also being studied in Head Start.

"You can impact both social, emotional and the pre-academic skills at the same time, in the same classroom, with the same teacher, without overwhelming the teacher," Griffin said.

Bierman next wants to train parents to reinforce these lessons. Meanwhile, her advice for parents:

¦ Ages three to seven are a key window for learning self-control. Talk to youngsters daily about their feelings and how to work through problems. Who did they play with? What made them happy? What made them sad?

¦ Get a misbehaving child to take a deep breath and calmly explain his or her feelings. That doesn't mean give in. But saying, "I see you're sad but it's still bedtime", helps children learn they can feel upset but still meet obligations.

¦ Parents should calm down, too. "It doesn't help to use your words if you're just yelling," Bierman notes.