Some medical conditions that cause IDs are easy to identify at birth. Other causes of intellectual disabilities make them more difficult to spot early on. In these cases, the child's caregivers or teachers are usually the first notice something unusual about a child's development. When caregivers are concerned about their child's development they should talk with the child's doctor. The early identification of an ID helps both the child and the entire family.
Some medical conditions that can cause ID are associated with obvious physical features. These physical signs are so noticeable they are easily identified at birth. Certain facial features are diagnostic of some medical conditions. For instance, fetal alcohol syndrome (FAS) is a leading cause of intellectual disabilities. The facial features of FAS include small eyes, small head, flattened face, and thin upper lip. However, physical features vary according to the cause of the disability. Some people with IDs have a perfectly normal physical appearance.
Another early sign of an intellectual disability is developmental delay. Children with intellectual disabilities sit, walk, and talk later than other children do. As children grow older, caregivers may notice difficulty with practical life skills. Examples of practical life skills are self-care and safety. Children might have trouble dressing or feeding themselves. Likewise, they may not understand and avoid dangerous situations.
Other functional problems become evident as well. One problem is logical and abstract thought. A deficit of this type means children don't generalize from one situation to another. They have trouble seeing the relationship between similar but different things. Instead, they think in concrete terms. For example, suppose a child saw an obese man in a grocery store. She shouts out, "Look Daddy, that man is fat!" As a result, her father explains this is impolite. A child without an ID would understand this social courtesy applies to all obese persons. It doesn't matter if they are in a grocery store, or a movie theatre. Similarly, the abstract principle of sensitivity to people's differences would be understood. Therefore, she realizes she should not shout, "Daddy, look, that lady is missing an arm!" This sort of understanding requires the ability to think abstractly and to generalize across situations. A child with ID cannot easily do this.
A related difficulty is the slower development of social skills. This becomes evident when children play together. Individuals with ID struggle to understand and heed social rules and customs. Some common examples are taking turns and waiting in line.
While some children's symptoms are easily detected at birth, others are not. Most times IDs are not detected until a child starts school. Education challenges children to develop and expand their cognitive, social, and emotional skills. Children with intellectual disabilities cannot easily meet these challenges. It is hard for them to learn new information as quickly as other children do. They also have trouble retaining that information. It is not always easy to spot these mental limitations outside an academic setting. The specific cause of the disability usually determines how quickly it can be identified. We discuss these causes in another section.