Birth order raised again

The findings suggested that the mechanism behind the birth-order effect is not biological but related to social interactions within families. He surmised that older children are showered with attention early in life and treated as leaders in the family. They are handed more responsibility after younger siblings are born and live with higher expectations from their parents. The recent study on birth order will spark more discussion. The key points in the article I read are boldened for emphasis. "Surmised", the researcher is making sense of the data in his own terms. "live with higher expectations", would it hurt to have great expectations of someone? What do you think?