My 12 month old is very busy and independent. He does not like cuddling and does not like to be restrained for long periods of time. He is ok with being in his car seat but for some reason does not like being in a high chair. This makes going to family dinner with in-laws very difficult. He wants out of the high chair after 10-20 minutes but dinner lasts much longer than this at my in-laws. We feel like we’ve tried everything. We do keep him in the high chair for the full dinner usually and kindly tell him dinner is not over yet. But, he flails around in the high chair and throws a fit when hes done eating and wants out to play.
Squirming in a highchair once hunger is satisfied is the norm, not the exception; your 12 month old is doing what almost all 12 month olds do. Your in-laws have unreasonable expectations. Unfortunately, neither your in-laws nor your child are likely to change in the near future, so you need to do what you must in that situation.
Getting down is not the only option. If he has a very favorite finger food, now's the time to give it to him. This might buy you a few minutes. Most toddlers like novelty; before he grows frustrated, give him a small toy or two which are brand new to him. He is likely to explore them happily for a few minutes. If there's a cup to put them in and take them out of, so much the better. A soft plastic sandwich bag filled with homemade colored slime (there are loads of recipes online) that he can squish is interesting, especially if there are small objects in it that move with the squishing. A small bin with blocks in it may entertain him. A tube he can drop something into and watch come out the end is fun, too. Search online for activities that may keep him happy in his seat for a while. This is not spoiling him. This is respecting the person he is, which is an active, curious person with a lot of energy.
This will be a temporary fix; eventually he will want to get down before everyone is ready to leave the table. You can try politely excusing the interruption to get him out. Have some toys set up somewhere (maybe a playpen nearby) and let him play. This might buy you some more time; you know your baby and I don't.
My in-laws/his grandparents make a lot of negative comments about how he’s “always busy” “can’t sit still” things like that.
The in-laws are being unreasonable. Either they don't remember their own babies or parented differently than you. Perhaps they were authoritarian parents who expected children to obey or act like small adults. The Authoritarian Parenting style has been shown to be harmful to children enough that I hope I don't need to support it with references. Authoritative parenting is much better; some people are permissive parents, some uninvolved. Maybe the best is the parent with varying approaches in different situations, taking into consideration what is best for their child long-term. Read about the different parenting approaches and decide which is best for your family. Then, follow your instinct.
The more difficult task is dealing with the negativity of the other adults, and you'll need to figure out the right approach with your husband. He should be protecting your child from his family's negativity, and you from your relatives. Although negative comments might fly over your toddler's head at the moment, they won't always. The time will come when your child will be hurt by them, and as a parent, you're responsible for protecting the feelings of your child, not those of other adults who should be handling their own feelings. Making negative comments is a way for an adult to try to control a situation instead of dealing with their emotions themselves. You might point this out playfully ("This is normal for his age. You only have to deal with this for a few minutes; I have to deal with this all day!") or enlist them in the solution ("If you have a good suggestion for keeping a one-year-old sitting quietly at the table, I'm all ears! You've had more practice at this than I have.") You might even suggest an alternative to bringing your child to dinner ("Would you like us to have a sitter watch him so we can have a peaceful dinner next time?") Or, you can let it go if it will cause a terrible rift. Whatever you and your husband come up with. But remember: you brought your child into the world and he is your responsibility. Do what's best for your child, not disapproving adults.
My in-laws were authoritarian parents; they believed in crying it out, etc. They also believed that they knew best. When my oldest just turned 10, we were moving into a new house (always stressful) and my in-laws were helping. I should have anticipated a problem and arranged for my children to be elsewhere while we were moving, but unfortunately I did not. My oldest asked to do something they loved to do and usually did at that time for half an hour and I (probably unwisely) said yes. When my FIL saw they were not helping, he made a hurtful comment to my child ending up with labelling them thoughtless and lazy. I responded (in front of my child), "Grampa, I gave [X] permission to [do Y] for half an hour. Please don't parent my child when I am present, and please don't talk to [them] like that." He responded, "I'll talk to [them] any damn way I please." The conversation did not go well, but my responsibility was to my child, not to a short-tempered and ill-mannered adult. As Ben Franklin said, "An ounce of prevention is worth a pound of cure," though he was referring to flames of a different kind! The moral of the story: anticipation is key.