One disadvantage of using parental reports to measure infant temperament would be that every child is essentially "perfect" in the eyes of their parent/guardian. They are not likely to see the flaws that others may be able to see due to the "rose colored glasses".
One advantage of using parental reports to measure infant temperament would be because they are around their children most often, for the most part. They know their child inside and out and can tell you if something is "off" or different about the child. They can give you an in-depth look about how their child's temperament is.
