First: Islam teaches us to be good tempered with all people, including one's spouse, children, students, etc., because the Quran and the sayings of the Prophet's household have commanded us to be good-tempered with others.
Second: According to the teachings of the Ahlul-Bayt, while being good-tempered with others we must also be careful not to go beyond the limits in this regard, meaning that we must follow moderation in this deed, so that others would not take advantage of it. In other words, being good-tempered can only stop others from taking advantage when supplemented by asking for one's right. At the same time we must keep in mind that being harsh and having a bad temper differs from having glory and majesty , and we must tell these two attributes apart, and finally we should know and observe the limits of good-temper.
One of the great features of Islam is the moderation that is found in this religion in all fields; in economy, politics, society and associating with others.
Most people assume that being good-tempered, or as it said these days, having successful public relationships means to consider every other person as your friend, the same way some Christians promote their religion as the symbol of love and friendship and claim that one is not complete unless he possesses nothing but love and friendship; some Hindu religions also believe in the principle of pure love and friendship.
But one must say that: Love and friendship are necessary but not enough, to have a friendship that is based on reality and seeking the truth is needed, for it is this type of love that can prevent the misuse of others. Islam is a religion of love and friendship. The Quran mentions the prophet as " رحمةً للعالمین " (a mercy for all people). The Quran also commands believers to treat people in a good way and that if ignorant people offend them, to overlook their mistakes. The friendship that the Quran approves of is not to act according to the other person's will and allow him to wish whatever he wants or to accept his wishes and endorse them, but rather Islam is always on the side of the truth in all issues; when associating with a spouse, students, children and etc.
Some ahadith that have mentioned the features of a believer, say: Among the features of a believer is that he accepts the truth from his enemy and he will not accept falsehood from his own friend.
If one associates with others in the mentioned way, not only has he taken the path Islam has approved of but he will also stop others from taking advantage of him, because either the people we deal with have correct and justified expectations or they are associating with us to misuse us and take advantage and ask for things they do not deserve, in this situation when acting based on the truth and reality, they will not reach their wishes. For example, if someone wants to take advantage of your good temper and offend you or others or take away your rights, in this case you must stand up to him even if he is the closest person to you. Moreover, love is only true and deep when it benefits the beloved one and does them good, for in some situations being too kind and loving without considering the implications, can actually be betrayal. In a hadith Imam Baqir says: " شر الآباء من دعاه البرّ الی الافراط " (The worst of fathers are those that go beyond limits when being kind to their children).
Of course none of this should allow any of us to justify our bad temper or ignorant behavior with others, instead one should strive to be good-tempered as much as he can and fulfill other's requests.
Therefore generally, having a moderate attitude along with a truth-seeking attitude is what is acceptable in Islam. There are ahadith that emphasize on being kind and friendly to people that one has authority over (like one's wife or children).
In regard to treating the smaller ones, the fourth Imam says: "The rights of the smaller ones, is to have mercy on them when learning and overlooking their mistakes and covering up their faults, being kind to them and helping them.
Generally, we must follow moderation in all fields. It is obvious that distinguishing the moderate path in different situations is not an easy task, to the extent that sometimes it requires consulting with learned scholars and benefitting from their opinions.
 Majlisi, Muhammad Taqi, Bihar al-Anwar, vol. 64, pg. 310.
 See: Motahhari, Morteza, Jazebeh va Dafe’eye Ali, pp. 10-13.
 Yaqubi, Ahmad bin Abi Yaqub bin Jafar bin Wahab, Tarikh al-Yaqubi, vol. 2, pg. 320, Beirut, Dar Sader, without date.
 Kuleini, Muhammad bin Yaqub, Kafi, vol. 4, pg. 11.
 " و اما حق الصغیر فرحمته و تثقیفه و تعلیمه و العفو عنه و الستر علیه و الرفق به و المعونة له "