How should one respond to a younger sibling asking for your help to cheat? Lets say a high school exam.
How responsible is an older sibling for the younger sibling's decision to cheat?
Where would an older sibling's role end?
I think the first step is to find out why they made the decision to cheat. This isn't to justify the decision, but rather better understand what drove them to this (e.g. laziness, desperation, peer pressure, etc.) so that you can tailor your response.
I feel that an older sibling shares a (small) portion of the parental responsibility: they have the obligation to be a role model, and help with ensuring that the younger sibling(s) is protected from dangers.
The response should be influenced by the relationship between the siblings, the reasons behind the cheating, and the relationship with the parents. First and foremost, though, the older sibling needs to respond with the younger siblings long term interests in mind.
I don't have any siblings, so I can't really speak to the obligation of sibling to sibling, but I do believe that it is the right thing to do to bring the situation to the parents, if this is in the long term interests of the sibling. Sometimes you have to risk hard feelings in order to protect those you love. Which is worse? Your younger sibling feeling betrayed by you, or your younger sibling developing a pattern of avoiding responsibility, lying, and cheating to scrape by life's challenges?
The older sibling is not responsible for the younger siblings decision to cheat. Lets say the younger had asked some one else - absolutely not the older child's fault. However, the older sibling is responsible for "aiding" in cheating if he/she decides to go ahead and help.
Assuming the elder just wanted to help the younger and went ahead and gave the younger paper/answer key etc. so he/she could cheat: I would personally discuss with the older sibling the idea that the older sibling already learned the material covered when he/she was in the class, but if his/her younger sibling is cheating than he/she isn't learning what he/she needs to learn. By helping with cheating, the older sibling is actually hurting the younger's chances of ultimate success in feeling good about the accomplishment.
Another answer discusses an older sibling needing to be responsible enough to consider the child's long-term-interests. While this is true, many parenting cultures can be quite punitive so I would just clarify that the older sibling is still a child and shouldn't be admonished for not having considered this. Instead, use the infraction as a chance to teach the older sibling HOW to. I would then let it go unless it happened again.
I also caution against instructing your kids to just tell on their sibling. Tattling can create huge rifts between siblings and in this case, there are a lot of in-between responses an older kid can have. Kids should involve an adult right away if anyone is getting physically hurt or has the potential of being physically hurt and that should always be CRAZY CLEAR. However, In regard to this topic, there is a little more grey area and some in-between options (a couple outlined in paragraph below). This part depends upon age and level of maturity, but teaching a child how to have an influence themselves can be a far more valuable lesson for the child later on in life than just asking them to default to telling you about it.
Instead try this: After the older sibling understands the long view, ask him or her what he or she thinks could have been done to help the younger sibling not cheat. Then play out the natural consequences of the solutions that are brainstormed in your discussion together. Tattling can be one solution, but so can saying, "I won't help you because. . ." while trying to persuade the younger sibling away from cheating altogether, and "If you do decide to cheat, I may have to tell Mom and Dad about it" and then lett the younger sibling make the decision from there. Try to be open to the older siblings ideas and give them time to get entire ideas out and developed. Ask your older sibling questions like (just keep them calm and in an open tone), "How do you think that would have turned out?" "How would you have felt doing that?" "How do you think your sibling would respond?" "What are the long-term benefits of that decision? long-term negatives?" Decide on a list of options the older sibling had together this way. You can't predict every outcome and what is done is done, but the exercise is a good one for critical thinking and decision making. It also gives your child the message that there are always options available - including going to Mom and Dad for help.
The younger sibling would also get a separate discussion. First, a lot of listening about the justifications etc. the child offers up. After assuring the child I understand through asking clarifying questions and paraphrasing, I would do what I needed as the instructive parent. If I believe the child is feeling the weight of too much pressure I would start by doing what I could to alleviate that pressure (at the moment of the discussion I would admit to my own mistakes before discussing theirs). Part of that statement can include, "I wish you had told me this BEFORE you cheated, because I am your parent, which means I am here to help and guide you. No that you have cheated though we have to deal with that too."
AFTER hearing the child out, I would go about discussing the pitfalls of cheating, how it hurts friends/siblings to bring them into doing something wrong by putting the co-consiprator in a difficult position (because he/she loves you and wants to help) AND go from there. This is also the time to discuss what school is for and the long-view in terms of learning goals etc.
In general, in my experience if you are a parent that focuses mostly on effort and the learning process, you are not likely to run into problems with cheating anyway (maybe once as an experiment, but not recurring). In ten years of teaching (In private schools) my middle schoolers rarely cheated unless they had parents that were very outcome focused.
An older sibling can share the same responsibilities as parents do if the duty is within their realm of expertise such as but not limited to
All one can do is offer guidance and help but ultimately the decision and ramifications are on the individual. In this circumstance, parents/siblings can only offer guidance and hope for the best. It's not like you can babysit the child as they take the test to ensure they don't cheat.
The older sibling can make the parents aware, not to tattle but so the parents can see if they have noticed patterns of stress or worry and offer their help too. Parents who are engaged in their kids' lives won't seem all of a sudden interested. They already know the exams are coming and can try to figure out the underlying cause of wanting to cheat.
If the parents are not that interested in the younger child's academics, then the older child can assume a higher responsibility if they can afford it with money or their own time (hiring a tutor, tutor their sibling themselves).
Usually a sibling has a better chance of getting through to the younger person and especially in this case since they have already enlisted their help (even though it was for cheating). What the older sibling says will affect the impression the younger child has of them. The younger sibling may not necessarily follow through even if an older sibling pushes them towards cheating. It may have just been worded like that as an attempt to ask for help, any help or just a form of venting.
If the older sibling/parents do not want to promote cheating, they should offer tutoring or direction on where to find tips/tricks. There are sometimes little mnemonics or short-cuts depending on the subject. The older sibling should definitely follow up at least after the test to find out how it went to show they care.
Here is a toll free number for help with school called Dial-A-Teacher and Homework Hotline funded by PBS: 1.888.986.2345