Final answer:
Characteristics like intelligence are strongly affected by both heredity and environmental influences.
Step-by-step explanation:
The statement that is true about hereditary and environmental influences on development is: 3) characteristics like intelligence are strongly affected by both heredity and environmental influences.
Our genetics (heredity) provides us with certain traits and potential, but our environment plays a crucial role in how these traits are expressed. Intelligence, for example, is influenced by both our genetic makeup and the environment in which we grow up. Studies have shown that both genetic factors and environmental factors contribute to intelligence, and it is not solely determined by one or the other.