Q: I have two boys, ages 31/2 and almost 5. My husband is a tugboat captain who is away for several weeks at a time. This has always been our family’s norm, but recently my older son has started to miss his daddy and act out while he’s away. He often cries himself to sleep and refuses to talk to my husband when he calls. He is aggressive and hits kids at school. How can I help him?

A: I have to confess: The tugboat captain husband fascinated me. The lifestyle seems to be so far away from my own, yet as I reflected on what this letter is about (separation), it occurred to me that many of my clients are dealing with the same problem.

Whether their parents are on a tugboat or traveling for business trips, children miss them when they’re gone. Before we can understand your son’s behavior, we have to understand the importance of how children handle separation.

From a developmental-attachment standpoint, separation is the primary issue that children face as soon as they are born. Without a deep, warm connection, a human cannot develop and mature properly, so babies will cry to bring an adult to them. The younger the children are, the closer the physical connection needs to be, and as they mature (if everything is going well), they will be able to tolerate more physical distance from their main attachment.

What does this look like? A baby stays near a loving adult nearly constantly. One-year-olds begin to crawl and walk, but they are always within eyesight and quickly scurry back to their loving adult. Two-year-olds begin to discover more and more of the world yet are always checking for their loving adult behind them. Three-year-olds can really begin to strut and feel more confident, but they will become cuddly and needy when near their loving adult. Four-year-olds will show greater interest in the outside world, and their imagination will blossom. They will also need deep physical and emotional connection. (The conversations become more important.) Five-year-olds are usually spending a good amount of time away from their connection and can handle it pretty well . . . until they can’t. Five-year-olds will have tantrums even if they have a good deal of language available to them.

As children mature, they can shoulder more separation from their attachments, but they will still need their connection cup filled. So, what happens when the separation becomes too much to bear?

Frustration. Lots and lots of frustration.

Because your 5-year-old is still fairly immature (meaning, he is not able to reflect upon his own mind regularly), he experiences the feeling of separation as pure frustration. The aggression is a sign that he is in pain, not that he is bad or needs more discipline. If he were mature, he might be able to say something like this to you: “I just spent so much time with Dad, and I loved it. We went hiking and he hugged me and we laughed and played, and now he is gone. I miss him, and my heart hurts.” This hurting heart is vulnerable. When his father calls, it is such an alarming emotion that his brain jumps in and says: “No. Nope. Talking to your Dad is going to hurt your heart again. Don’t talk to him.” It isn’t that your son doesn’t want your husband; it is that he wants him so badly that his brain is defending him against the pain.

Pent-up feelings of alarm, separation and frustration manifest as hitting. When children can’t handle the big emotions swimming around inside them (because of immaturity and vulnerability), the emotions come out in other ways — and in the case of your son, through hitting.

How can you help your son lessen the feelings of separation and hence lessen the incidents of aggression? Here are a few ideas:

1. Stop any and all separation-based discipline techniques. This includes traditional timeouts and being sent to his room alone. While it is tempting to punish him, if we think that separation is the problem, more separation will only cause more behavioral problems. If you need to remove him from the family, the room or the table, go with him. If he needs to sit down to cool off, sit with him. I know I am asking you to parent more, but trust me: This will shorten the duration and severity of the tantrums. Staying with your child communicates safety and connection, just what your son’s young brain needs.

2. You need to help Dad connect strongly to your son when he is home. A simple routine would be best — something that they always do, no matter what, just the two of them. This can and should be easy, inexpensive and not dependent on too many factors. The trick here is that it must be treated with the same importance as other priorities. I understand that life gets in the way here and there, but the point of this is to make your son feel safe in his connection with Dad.

3. Create a tradition around Dad leaving on his trips. Hang a calendar that is clearly marked with the days he will be gone. Have your children mark off those days and frequently discuss the next time the family will see him. Be sure to have Dad leave behind an undershirt or another piece of clothing that really smells like him for your children to cuddle and sleep with. Have your husband make voice memos of him reading books or telling stories so that the children can hear his voice while he is gone. Put family pictures near their beds and highlight pictures of them with their father.

4. Most important, help your son miss Dad and find his tears around that. The more your son can cry about what he cannot change (his dad being gone), the less likely he will become frustrated and aggressive. I think of a hitting child like a sheep wearing wolf’s clothing. Under the ferocity and snarling, there is a soft heart that needs some tenderness.

5. Give this time. Don’t expect overnight changes, and please bring the school into this. Have the teachers help your son by embracing his sadness and frustration. Of course, everyone has to keep children safe. (Stop the hitting, for sure.) Just be aware that any shame or punishments will increase his aggression. Good luck.