Morale, also known as esprit de corps when discussing the morale of a group, is an intangible term used for the psychological capacity of people to maintain belief in an institution or a goal, or even in oneself and others. The second term applies particularly to military personnel and to members of sports teams, but is also applicable in business and in any other organizational context, particularly in times of stress or controversy. Generally speaking, when a person or group is poor (or broken) morale, accomplishing even simple feats can be nigh impossible. Conversely, when a group's morale is high, often they will overachieve in their goals to the point of legendary accomplishments.
While the Zombie's simple intelligence is usually it's major disadvantage over humans, one notable exception is their universal immunity to psychological warfare. Quite simply, their spirit cannot be broken, no matter what is done to them. This can be a devastating psychological advantage over humans opposing them, as illustrated in the Battle of Yonkers in Max Brooks' World War Z.
A Hot Meal & Good Food: Depending on your conditions, cooking may sometimes be problematic. Heated food is a proven morale booster. Never underestimate the bonding that can be shared over a hot meal. This could range from the simplicity of scrambled eggs to the luxury of chocolate chip cookies.
Alcohol: A sip now and then never hurt anyone, but one must be careful. Fighting zombies is hard enough without seeing double. It can be anything as long as it is not too strong. A good choice is to mix it with something so it isn't as strong. Somethings to mix it with are cola or orange juice.
Animals: Animals are known to boost morale. On an emotional level, owning a pet can decrease depression, stress, and anxiety; health-wise, it can lower blood pressure, improve immunity to common ailments, and can even decrease the risk of heart attack and stroke.
Cigarettes: Cigarettes stimulate the flow of "feel good" chemicals in the brain, such as dopamine. Cigarettes are, obviously, a health risk and should be consumed in extreme moderation.
Finding a gun: In an apocalypse where guns are essential for survival, finding a firearm and adding one more layer of defense will be a great booster.
Clean water: Water is the requirement of all living things drinking, clean water when dehydrated is said to be one of the best feelings ever.
Hygiene: Looking and smelling clean, or even the feel of water washing away all the grime, can be a great morale booster.
Humor: Lightening the mood, even under the grimmest of circumstance, can go a long way in increasing morale. One must always be aware of the sense of humor of their colleagues and try not to offend them (for example, no Polish jokes until you're sure no one is Polish, or has Polish loved ones). Sometimes, the rudest jokes are the funniest, and most memorable. But one must always be sensitive to the feelings of others, otherwise, it defeats the purpose of using humor to defuse a tense situation. It can be a process of trial and error.
Junk Food: Although bad for you, junk food such as chips, candy or even cereal can be a nice reminder of a pre-zombie life. Could also be a small change from a bland diet.
Light: Constant darkness on a base can lower morale extremely fast. Candles or flashlights may help.
Movies: If you find a TV, a movie, and have enough electricity, this will be a fantastic morale booster, if one can spare the resources to operate a television.
Games: Non-electric games, such as board games and dice RPGs can keep people very entertained. If the necessary power is available, video games can be very entertaining as well.
Music: The sound of music can stop harsh thoughts of hopelessness, drown out constant zombie moans, occupy the brain, draw common bonds between survivors, or even make zombie-killing entertaining if played at the time. However don't force music or constantly play the same tune, as it can lower morale.
Other survivors: Knowing that others are alive and you aren't the last person alive will greatly boost morale.
Physical Contact: From a high-five, to a hug, to an act of sexual nature, it reminds us that we are human, and even in such times everyone needs skin to skin contact to feel that we aren't alone.
Reading Material: Magazines, Newspapers (not that will be 'new' news), Novels etc. will provide a quiet haven from the chaotic world around you. Some books may contain knowledge needed for survival, from car maintenance to medical treatment.
Religion: The greatest comfort some possess is the belief that there is a greater power looking out for them with a plan. Although the events of mass death, zombification, and the collapse of civilization can lead to a crisis of faith.
Rule 32 (Destruction as Entertainment): As stated in the movie Zombieland, enjoy the little things. If it means destroying things, so be it.
Wanton Violence: When the opportunity presents itself to safely kill a zombie that is otherwise not an immediate threat, killing them creatively or gruesomely can be a bit of a stress release, or a laugh.This may not be everyone's cup of tea, so judge your troupe carefully. Also, no conflict is ever 100% safe or certain. Always actively take safety precautions. Direct exposure to the undead should always be limited, and resources should never be wasted.
Death: The greatest pain a person can know is the loss of someone dear but the important thing to remember is that they would want him or her to survive. A person can't help anyone if they are overtaken with grief. Try focusing on other things to get one's mind and the minds of the group off of the subject and onto something that will prevent another loss.
Loneliness: No matter how lone wolf you are, knowing someone is there for you can prevent depression or suicide.
Hopelessness: Regardless of actions taken, success is impossible- or the certainty that future events will turn out for the worse no matter what you do. Hopelessness can stem from your health, caring for others, thoughts of returning home again, and seeing loved ones again.
Fear: Fear is to be expected in the face of zombies. Some might say a total lack of fear is foolhardy, and may lead to fatal mistakes. Much more common is being overcome and paralyzed with fear. Be wary of those who may buckle under pressure. Encouragement from kind words to orders to toughen up may help. Everyone responds differently to different stimuli.
Constant Moaning of Zombies: An underrated and devastating "secondary weapon" of the zombie horde is their constant moaning. As zombies do not sleep, they moan for reinforcement non-stop, day and night. While barricaded in a base, this constant reminder can easily drive people insane. A soundproof base, while a rare luxury, is greatly valued for this reason. Earplugs may be effective at warding off this psychological assault. Otherwise, the only way to silence the walking dead is to kill them all.
Resentment: An emotional state of displeasure toward some act, remark, or person. To sum it up..if traveling in a group only travel with people you can tolerate. If that is not possible play nice and try to maintain a sense of humor.
Anger: Inability to satisfy your needs or wants. Don't get mad and do something about it.
Boredom: Although there will likely be a lot to do to, boredom can occur, especially if you are unable to perform tasks, or need to perform the same monotonous tasks over and over again
Darkness: Can cause fear and paranoia of any noise around.
Zombification: Someone in the group or a group member seeing a friend or family member zombified is a harrowing experience.
Base Location: Taking refuge in dreary locations, such as prisons will lower morale, which prisons are designed to do.
Loss of Base: Losing your base and being forced to relocate will be sure to lower morale, especially if you had it for awhile.