As a new parent, I'm well aware that you cannot spoil a baby, and my wife and I enforce that. However, at what age (or level of the child's ability) should we begin easing off this ideology? Are there signs we should look out for in toddler-hood?
It would help if you would define what you mean by spoiling. People have all sorts of ideas on what spoiling means. I have been told many times I spoil my kids, yet overall, my kids are given less material items than most kids I know and they also have stricter limits on many things than other kids who may have parents who think I spoil. My mother in law thinks I spoil my 10 year old because he is permitted to talk to me (in venting form, so complain) when he doesn't like a decision we have made as parents. I am not at all giving him the impression my mind is changeable, nor is he insulting or rude with his words. I permit this because I think it is normal for him to dislike something he disagrees with, and I feel it's a valuable lesson in learning how to express your unhappiness in a suitable way. I also want him to know I care about how he feels, and that I can make a decision that I know he hates, and that doesn't mean that I don't care about how he feels about how that impacts him. I would much rather he tell me how unhappy he is with me than complain to a friend. At least this way I am aware of what he is thinking. My point is, my mother in law thinks this is indulging him. I am not sure why it bothers her so much, but it seems to. It has never resulted in me changing my mind, so it's not like he is trying to talk me into it. I personally find it good for my relationship with my kids (I have two grown now too) and feel it makes them believe that I am open to hearing everything, not just the happy shiny stuff.
I also think sometimes people call things spoiled that couldn't possibly fall under that category. Nearly any child who is rude to their parents might be called spoiled, yet that child might in fact not get much at all, in regard to material items, attention, anything. The lack of investment can in fact elicit behavior that many would compare to spoiled behaviors.
People also can easily on the surface misinterpret things. I do not use the word no with my kids. There is a simple reason. It has gifted me now 5 kids that have never said "NO!" to me, not at all. It's just not a word I use frequently. That doesn't mean they get to do whatever they want. Very likely I have more boundaries than many who use no often. I simply rephrase. I say things like "We can do that later, when this is picked up". If it's a simple thing I replace no with words like "hands off", "feet on the floor please", "here trade me that for this". It simply works better in my experience. There is less friction, the child accepts it well and life flows easier. People love to say "Children need to learn no means no". We sure. But seldom really in life is "no" the answer given to adults for anything meaningful. Usually, in life, you get some context with it, like when I recently told my husband I want to add a deck to our 2nd story. He didn't say no, but he gave me a quick dose of reality with a little factoring on pricing and what he really meant was no. Likewise when he proposed a huge garage I didn't say no, I explained though that it would eat up too much space that is currently required for the kids to have good outside play and that it would be far more feasible in 5 years or so. That is how life generally is. If my kids ask me if there are more cookies, and they are gone, I do say "no". I just don't use it as a corrective word or in response when I can find another way to answer. But I have heard people mock not using "no" and imply it means you let your kids run amuck and they are clearly spoiled.
TL;DR You will know if you have gotten off track in parenting based on your child's behavior. If you have (and they aren't just 2-3yrs old, because frankly those years are iffy even for great parents), then you make corrections. One of the best ways to do that is simply focus on connecting to your child. Model behavior you want them to emulate (so avoid raised voices, letting your anger get hold of you, becoming reactive) and instead give them short clear statements on expectations, so they know what you want versus telling them what not to do. Feed them good food, develop a routine that works well for everyone, hug and kiss them a ton, listen (intently and without distraction) as much as you talk, laugh as often as you can with them and you will sort it out, even if it's gotten off track. That formula will work from now until they are adults. I am still on that same formula with my grown girls.
From what I have found and observed as a parent of toddlers, there is a pretty large gap between spoiling a child and giving the appropriate amount of love, affection, discipline, and material desires. From what I have found, you will know you are on the verge of spoiling (and this applies to more than just children) when they feel/act like they are entitled to what you are giving them.
I caveat by saying that I believe love for your children should be an entitlement. They should always expect your actions to be ones out of love. They deserve this. However, in other aspects, mostly material items that we give them, expectancy tends to increase entitlement.
Queues of entitlement come in many forms. Most children tend to follow their manners and say things like "please" and "thank you", they are generally grateful of what they receive, and tend to be helpful when asked, assuming they have been taught to do such things. Remember, up to the age of toddler-hood and even past that, they are mostly mimicking our actions. If we don't teach them, they won't know that it is appropriate to do. If though they have been taught to be grateful and be helpful, yet they begin to act like they aren't, they may feel like they are entitled to such things and that's when we can probably say they are a little too "spoiled".
At the same time though, there is no need to rub it in their face that you are their provider. Instead, gentle reminders of "hey, remember to say thank you when you receive something from someone please" or "I know you may not feel like doing this thing for me right now, but it would really help me out and make me happy." Gentle spot corrections like this when they are young go a long way as they get older.
Just be mindful of their actions. There is no specific set of rules to look out for. If it happens, you'll know it.
Disclaimer: I am a father of a 2 year old and all I say is from experience and some reading. My perspective largely bases on the books of Jasper Juul.
I agree largely with SomeShinyObject. You cannot spoil your child with love at any age! But YOU are the one to say No to the child, when YOU think it hurts your, let's call it, "comfort zone" (this inner alarm bell, when your child is doing something that YOU do not like).
I refer to "spoil" as e.g. "giving the child too much sweets so that it will ask more often in the future". Same with toys and stuff.
The best advice I can give you: Defend your comfort zone and respect the comfort zone of your child. Do not listen to the expectations people around you have!
For example: Sweets from the supermarket. If the child wants some sweets and you are okay with that, buy him some. Do not (!) decline the child's wish, because you think the people around you want you to do so. That would make you unreliable for the child! However, if for some reason (e.g. there are still plenty of sweets at home) you do not want to buy more sweets, you tell the child politely but firmly that you will not buy more, becaus of [insert reason]. Subsequently, you will need to take responsibility for your decision by bearing the sort-term anger and frustration of your child (in this situation it is important to make no fun of your child or distract it from its anger. The first is mean and disrespectful and the latter is contraproductive, because your child needs to learn to handle frustration and anger).
"Spoiling a child" has a very vague and subjective meaning. How your child grows and learns really largely depends on your behaviour. Your child will subconsciously mirror you and your actions.
Hope this helps a bit! You just started a journey, no sprint. :)
According to "Dr. Spock's baby and child care":
So the answer to the question "Can a young baby be spoiled?" is no, not until six to nine months of age. [...] You can be a little more suspicious after six or seven months."
Spoiling is a key problem in modern affluent societies. We may define pragmatically spoiling as the act of giving and yielding too much to somebody. This can happen with children as well as with adults (eg a partner). Most importantly, it can happen even very early on, for instance when the mother is setting nursing times.
Of course, if you have the means, it would be nonsensical to deny something to your child just to make a point and let him/her grow unspoiled. Accordingly, we need to distinguish carefully caring from spoiling.
The key issue for a parent is to be able to set clear and fair rules, and then apply them. A spoiled child is a child who cannot abide rules, whereas a non-spoiled one, even if rich, knows rules are real and should always be followed. You really spoil a child only when you change your rules or contradict them for a whimsical child preference.
Just to give an example, a nursing mother who has chosen under pediatrician supervision to nurse her child at specific times, should try to stick to her chosen schedule and enable the child to conform to such schedule. Such a rule should not be regarded as a law, as child distress should be taken into account. Remember however that denying for instance an early nursing doesn't mean that the child cannot be cuddled in the meanwhile.